Top 45 Prospects: Arizona Diamondbacks

Robinson’s physical composition and athleticism drove club interest and netted him the fourth largest bonus in the 2017 international free agent class. Even as a 17-year-old on Arizona’s backfields, he stood apart physically from rehabbing big leaguers several years his senior, and instantly attracted evaluators’ attention, like the gravitational pull of a very dense star. And star is apt because that’s the kind of projection Robinson’s tools allow for. Big, fast, and prone to generating thunderous contact, he’s more physically alike to young SEC pass catchers than most of the baseball-playing universe. But the background — a giant, Bahamian man-child without the showcase track record of most of his Dominican peers — meant the industry knew even less about how Robinson would handle pro pitching than it did the average J2 prospect. After some initial inconsistencies, Robinson has not only quelled those concerns but also surpassed expectations, and in 2019 he clubbed his way from the Northwest League to full-season ball as an 18-year-old.

Robinson’s bat path lacks the lift necessary to produce in-game power on par with his raw, but the foundation of his swing is sound, with nothing too complicated despite Robinson’s size. He’s already hitting 50% of his balls in play with an exit velo of 95 mph or more, which is up in Joey Gallo/Nelson Cruz territory, it’s just often low-lying contact. Robinson’s fast enough to continue being developed in center field, but there’s a good chance he ends up on a big league roster with a superior defender who kicks him to right. His ceiling, that of a 35 homer force who can play a passable center, hasn’t changed since he first began appearing on the electronic pages of FanGraphs; his progress is just evidence that such a future is becoming more likely.

Varsho presents us, and other evaluators with anticipatory tendencies, with a bit of a conundrum. While we expect that future changes to the way balls and strikes are called (i.e. an electronic strike zones) will make it so below-average receivers like Varsho can catch quite comfortably, it’s also going to raise the offensive bar at the position in a way that alters how we think about catchers generally. Once framing became quantifiable, the average wRC+ at catcher went from about 93 down into the mid-80s. If that skill becomes moot, catcher offense will certainly rise.

Varsho’s case is unique, as is his skillset for the position. He’s a plus runner who might steal 30 bases at peak, a contact-oriented, gap-to-gap hitter with catalytic qualities found in old school one and two-hole hitters. How much of that spark erodes if Varsho is asked to take a beating behind the dish one hundred times a summer? Probably some, and when paired with his defensive shortcomings — he has a fringe arm, trouble catching balls cleanly, especially toward the bottom of the zone, and at times struggles to block breaking stuff in the dirt — there are suddenly several reasons to limit his catching reps and deploy him in left field, or perhaps try to hide him at second base. Varsho seems motivated to catch and he’s both quite athletic and highly competitive, two things that often help prospects carve paths to unlikely big league outcomes. So while we think it’s becoming less likely that he will be an everyday catcher, we’re still in on his offensive ability, makeup, and rare collection of skills, and remain intrigued by the proposition (and growing likelihood) that he’ll be a dynamic, multi-positional player who catches once in a while.

All of the left-handed hitters at the 2019 Futures Game had some help from the wind blowing out toward Progressive Field’s right field bleachers, but even with that aid, Thomas’ batting practice in Cleveland was surprising. He was about a year removed from falling to the 2018 draft’s second round in part because his stature didn’t allow for traditional, frame-based power projection, but he’s very strong for his size (Thomas’ dad is the White Sox strength and conditioning coach) and already has average raw at age 19. He’s well-conditioned, but short, built narrowly, and likely to max out with a frame (and skill set) similar to Brett Gardner‘s.

He lets balls travel deep into the hitting zone and sprays hard contact all over the field — about half of his extra-base hits were stuck to the opposite field last year, many of them doubles sliced into the left field corner. An unchanged approach to contact would likely result in limited over-the-fence power, but Thomas is fleet of foot and either projects in center field or, due to arm strength, as a plus-plus left fielder, which takes some pressure off the offense. There’s some tweener/fourth outfielder risk here but Thomas now has a four-year track record of hitting against pitching that is often older than he is, beginning with his performance on the showcase circuit as an underclassman and ending with an aggressive promotion to Hi-A toward the end of 2019. It’s pretty amazing that an undersized, young-for-the-class hitter from a cold-weather location has moved this quickly without a hiccup, and we’re inclined to believe Thomas will keep hitting and eventually become an everyday big leaguer.

At the lowest levels of the minors, it’s hard to tell if a ball/strike recognition prodigy is real or not because the opposing pitchers are often just incompetent strike-throwers. Perdomo’s 2019 exposure to full-season pitching put to rest concerns that we were previously overrating his diagnostic abilities, as he continued to grind out tough at-bats against sentient pitching, and walk at a 14.5% clip at Low-A Kane County before his August promotion to Hi-A. So confident is Perdomo in his notion of the strike zone that, after taking a looking strike three during Fall League, he flipped off the TrackMan unit calling balls at Salt River Fields.

That skill combined with Perdomo’s bat-to-ball ability from the left side (his right-handed swing is bad) and his elegant shortstop defense, gave him a promising foundation of skills as a teenager on the backfields. Then, the juice started to come. Perdomo’s exit velos climbed throughout 2019. He averaged about 80 mph off the bat at Low-A, then about 82 mph after his promotion to Hi-A, and finally averaged 87 mph during a limited Fall League sample. His body has become more mature, and his left-handed swing has become more explosive and now features an overhead, helicopter finish similar to Miguel Andújar’s. There’s still some room for improvement as it relates to the lower half usage in the swing, and it’s possible Perdomo scraps hitting right-handed altogether at some point. The skills/instincts foundation here is solid enough to project Perdomo as a low-end regular, and the burgeoning physical ability means he’s begun to look like quite a bit more than that.

Carroll was electric during his showcase summer, displaying consistent, high-quality, all-fields contact and, at times, surprising power. From a skills and present baseball acumen standpoint, he was perhaps the most polished high schooler in the whole class, but his sleight, narrow build slid him back behind more traditional-looking athletes, like Bobby Witt and CJ Abrams. Though he doesn’t seem inclined to turn on pitches and lift them with power, Carroll loudly squashed concerns about lacking physicality by hitting lasers all summer, first in the AZL, then later in the Northwest League. In addition to having plus pure speed, which will enable him to stay in center field and perhaps be an impact defender there, Carroll is also a sly, instinctive baserunner who presses action. The two unknown variables at this point are a) how Carroll’s lilliputian frame withstands the rigors of a long, full season and b) if the Diamondbacks will try to tweak his swing or approach to produce more power, since his measurable exit velos indicate he has a chance to hit for some.

TrackMan-focused teams were all on Martin the summer after his sophomore year, as he was showing three data-friendly plus pitches and starter traits while he closed games on Cape Cod. Due to a deep veteran staff at Texas A&M and his own inconsistency, Martin only really pitched for part of one season as a starter while he was in college. A lot of teams thought he was just going to be a reliever. The Astros popped him in the second round of the 2017 draft, hoping to tease out the traits they saw on the Cape, and in the two years he was in the org, they did it. Martin was a top 100 prospect before his elbow blew out late last June.

Healthy Martin sits in the mid-90s, mixes in a hard, upper-80s slider, has an above-average power changeup, a more vertically-oriented curveball, and average command. He made too many mistakes during his short big league look in Houston last year and gave up a bunch of dingers, but we think he’ll get his pitch execution issues ironed out and attack hitters the way most Houston arms do: fastballs at the top of the zone, sliders off the plate to the glove side, and changeups and curveballs down. Martin was part of Arizona’s return for Zack Greinke. We’ve diluted his FV a bit because we worry the timing of his surgery will mean he misses most of 2020, though Martin is a premium athlete and animalistic competitor, and people in his current and former org expect him to crush his rehab and be back as soon as possible. If his stuff comes back, we’ll 50 him again.

Bukauskas took time off from pitching and got in the weight room as a high school underclassman, and emerged the following spring with four or five more ticks on his fastball. He then reclassified and was suddenly on track to graduate and be draft eligible a year early, meaning every decision-making amateur evaluator in the country had to get in quickly to see a pitcher who had all this new velocity but with whom scouts had very little history. Then Bukauskas asked not to be drafted (he was, but late, and didn’t sign) so he could go to North Carolina. After a middling freshman year, he was dominant as a sophomore and in the early part of his junior year before his stuff was depressed during North Carolina’s postseason games. That dip inflamed perviously held concerns that durability issues resulting from his size and a violent delivery might push Bukauskas to the bullpen.

A 2018 car accident, which caused a slipped disk in his thoracic spine, limited Bukauskas to about 60 innings in 2018, which left questions about his ability to start unanswered. He was electric when he returned, though, and became increasingly dominant towards the end of the summer before his stuff was seen by the entire industry in the Arizona Fall League. He flashed 70-grade changeups and sliders on occasion, bumped 98, and has added a cutter, which it appears he has since scrapped. He was wild in 2019 and it’s becoming more likely that he winds up in the bullpen, though we think he could be positively dominant in that role.

Walston popped up pretty late, at a point in March when multiple clubs were sending in heat week after week to get some history. Some teams were out when they got multiple outings where he was mostly 84-89, while others are still hot on his trail. We saw him late when he was opening 90-93, cruising 88-91, and reaching back for 93 when he needed it. Walston was young for the class, ultra projectable, an above average athlete, and throws two versions of his curveball with the harder slurve flashing 65- or 70-grade when it’s on, while the slow one is a consistent 60. There’s feel for a changeup and command, and his fastball has life that enables it to compete for swings and misses in the zone even though it isn’t all that hard. Yet. He was up to 94 for Eric in the AZL after he signed. It will depend on how Walston develops physically, and how those gains counterbalance the coming full-season workload, but he has a chance to end up with three plus pitches and impact command. He’s as risky as any teenage pitching prospect, perhaps riskier when you consider those velocity fluctuations. One scout’s upward trajectory is another’s recency bias.

Patino had originally agreed to a deal with Texas, but it was voided due to an elbow injury and he eventually landed with Arizona. Toolsy, physical, and built like Trevor Story, Patino has an exciting combination of speed and power, as well as promising ball/strike recognition. What he lacks at this point is barrel control and a bat path that enables the power. Those are important components and may not be easy to fix, especially the bat control issue. But Patino’s ball/strike and breaking ball recognition could help mitigate those issues, and his ceiling (a high OBP center fielder with power) is lofty if they’re overcome.

Amateur scouts who picked up pro coverage the summer after the draft were in awe of Patino, who was the age of most of the players they had just spent a week discussing in the draft room but more physically gifted than all but a select few of them. A max-effort player with a fairly mature build, Patino may skip over short-season ball next year and head right to the Midwest League to be among athletes with more comparable physical ability, though that may mean he gets fewer reps in center because of Corbin Carroll’s presence there.

Duplantier had been injury-free since college (where he dealt with shoulder problems) until 2018, when he had hamstring issues in the spring, and biceps tendinitis later in the summer. The lost innings resulted in an Arizona Fall League stint, during which Duplantier was one of the better pitching prospects in the league. Despite the biceps issue, his velocity was fine in the fall, when he sat 93-96 and showed three good, clearly demarcated secondary pitches. Then 2019 came. Dup’s stuff was not as crisp during the spring, and he was shuttled back and forth between Triple-A and the big leagues several times; he had a shoulder issue in the middle of the summer and his stuff was down again later in the year. There’s a chance his stuff bounces back and he pitches like the 50 FV we thought he’d be last year, and there’s a chance those two-ish healthy years sandwiched by all the injuries are, in fact, the outliers.

We love how athletic Tabor is and how quickly each of his secondaries became good considering his Northeastern prep school background, but while some of our sources are inclined to continue projecting on his velocity because his build is still young-looking, we think two straight years of 90-93 (Tabor’s velo popped late in high school) makes it more likely the fastball settles here. He’s athletic, his arm slot creates rise on his fastball and bat-missing, vertical action on his breaking stuff, and Tabor has good changeup. We have him projected as a No. 4/5 starter.

Even though we saw him up to 96, we were not big fans of Kelly while he was in high school because he had a softer, maxed out frame and a stiff, violent delivery we believed would limit him to a relief role if his arm didn’t fall off first. Now, he has arguably the best physique in this system at a svelte 205, and was so dominant during minor league spring training that the org was compelled to send him to full season ball even though he was initially slated to hang back in Extended until short season leagues began after the draft. And Kelly delivered, striking out 126 hitters in 100 Low-A innings.

Often, a pitcher who remakes their physique will be rewarded with a jump in velocity. This is not the case with Kelly, who we still have averaging about 92 with his heater. What Kelly does have, is one of the better sliders in the minors, with a shape and bite similar to Brad Lidge’s diving bastard of a slider. Sometimes it comes out of Kelly’s hand high and arcs into the strike zone like a curveball; hitters still can’t touch it. Sometimes it backs up on Kelly and has changeup movement; doesn’t matter. When executed, it’s a big league out pitch right now. Kelly needs to refine his fastball command because it isn’t hard enough to live in the zone, and needs to live at the top of it. We think he’ll have to nibble with the heater and end up working too inefficiently to start, but we think he’ll be an excellent, multi-inning reliever.

In front of a huge contingent of scouts, Jameson carved up Stanford in his first start of the 2019 season and was immediately on the map as a draft-eligible sophomore. His high-maintenance delivery is hard to repeat, but it also makes things awkward for hitters, who don’t typically see this kind of arm slot/release point. And from that release point emerges nasty stuff. Jameson will touch 98, manipulates the shape of two good breaking balls, and flashes an occasional plus changeup. The delivery may make it hard for him to start, and Jameson has a skinny, atypical frame. Some teams think he ends up in relief, but it may be in a multi-inning or high-leverage role, and he’s held velo deep into games as a starter so he may have a shot to stick.

At times, Frias looks like a stiff, velo-only bullpen prospect. At others, he’s competing in or near the zone with four pitches, including a splitter that was much better in 2019. All four pitches give hitters a vastly different look. Frias’ mid-90s fastball has tailing action and his curveball has vertical depth and eats up hitters who are cheating on velo, while the split has late bottom when it’s on, and the slider has horizontal, cutting action. The movement profile of his fastball may not be the best for missing bats, but it’s likely to be an impact pitch because of the velocity. He could end up with three average secondaries (there’s a chance the split becomes better than that) and enough strikes to start, making him a potential No. 4/5 starter or late-inning reliever.

Middle infielders with power are rare and yet Young, who is exactly that, somehow lasted until the 37th round of his draft and signed for just $3,000. This is the Cardinals’ archetypical draftee — a power-first prospect with questionable mobility. Collect enough of those and through a combination of luck and good player development, some of them will turn into passable defenders and become solid big leaguers or tradable assets like Young, who was sent to Arizona in the Paul Goldschmidt deal.

This is our odds-on favorite to take up Wilmer Flores‘ mantle as the heavy-footed middle infield masher the D-backs turn to when they need runs late in games, or who they replace with a better defender when they need to prevent runs late. Though he does most of his damage on pitches on the inner half, Young has enough barrel control to spoil pitches away from him until he gets something he can square up. When Young connects, he does so with power. Buff and square-shouldered, Young’s physicality is a driving component of his power but it’s also why he’s somewhat limited defensively. Since being traded, he has seen time at shortstop, third base, and second; he projects as a 40 defender at all three spots.

We have a source who indicated to us that Beer’s exit velos have been slowly declining since his freshman year at Clemson, and that jives with reports of his overall athleticism and mobility, which have also been in decline since his historic freshman season. It’s an odd athletic trend for someone who was once a decorated amateur swimmer, since swimmers are always ultra sinewy and lean. It is common for baseball players whose bodies mature early to also start to decline early, at least in our anecdotal experience, and this is true of Beer, who was on the scouting radar very early as an old-for-his-grad-year (we really need a word for this) underclassman. Instead of reclassifying and entering the 2015 draft as an 18-year-old, Beer skipped his high school senior year completely and early-enrolled at Clemson. He went on to have one of the best freshman years in college baseball history: .369/.535/.700 with 18 homers, 62 walks, and 27 strikeouts.

In the few intervening years, Beer has continued to perform, his numbers slowly trending down as he reached his draft year at Clemson, then pro ball for a year with Houston before they shipped him to Arizona as part of the Zack Greinke trade. He’s now 23 and has a .294/.388/.508 career line in the minors. He reached Double-A in his first pro season. These are all good signs, and we’re almost certain Beer will be a solid big league role player relatively soon — we just can’t speak to what his shelf life will be and don’t think his ceiling is in the Rhys Hoskins/Pete Alonso realm at all.

There was late-Spring backfield gossip that the D-backs had a hard-throwing righty in the DSL who we might see in Arizona before the summer was through. On the day before his 18th birthday, Martinez threw an inning of AZL ball and bumped 98 on the Chase Field gun. Perhaps more surprising than the velocity, which we had been primed to see, was how well Martinez executed his breaking ball over his next couple of outings. It’s only an average tweener breaking ball right now, but he consistently located it down and away from righties, enticing them to flail at it as it disappeared in the dirt. Eric saw some average changeups, as well. His fastball control is certainly raw, and while Martinez has a strong, projectable frame, his arm action is somewhat odd, with less external rotation going on than with most elite velo guys.

The D-backs need to work on getting Martinez behind the baseball so his fastball doesn’t have cut action (it’s not enough cut to be impactful, it’s just running into barrels, as you can see on our high speed video of Martinez) and instead has ride. That should come with time. Were Martinez draft-eligible, he’d go somewhere in the second round.

Alexander fell out of the top 10 rounds of the 2018 draft due to questions about his signability, hit tool, and age relative to his peers. He was almost 19 on draft day, which, combined with the strikeout issues, moved him way down the boards of teams who care about those variables, especially together. He ended up signing for a very reasonable $500,000. At the time he was seen as an advanced defender with an 80 arm (the teams most bearish on his bat in high school wanted to see him on the mound) and above-average raw power, which Alexander’s pre-daft proponents insisted he’d get to despite the strikeouts. Pro scouts who saw Blaze in 2019 did not quite drop a 55 on the power (which is supported by his TrackMan data) and called him “streaky,” which they perceived to be caused by lapses in focus. He had a strong statistical season, played several positions well and showed an encouraging idea of the strike zone, so we’ve held over his FV from last year despite the dip in reports on the power.

Henry was a strong follow for the 2019 draft, sitting 87-90 in 2018, but took a big step forward in his draft year, coming out of the gate at 89-92, touching 93 mph. Later in the spring, his velo tailed off and some teams moved on, but it came back right before the draft with a strong postseason look for the National Champion Wolverines. Henry was nearly 22 on draft day, so his velo dip was more concerning, but we’re told an injury was to blame. His style of pitching, with deception, great body control, and a high arm slot, fits what progressive clubs generally, and Arizona specifically, are looking for, with vertical movement on the four-seamer and 12-6 action on his curveball, which flashes above average when his arm speed is there. His changeup also flashed above average at times and one scout we spoke with thinks there’s room for another 10-15 pounds of muscle even at age 22, giving him a No. 3/4 starter workhorse profile if things work out.

Fletcher was a tweener outfielder as a SoCal high school prospect. He matriculated to Arkansas, where he slowed down a bit but grew into more power than expected. He still has a slasher-style swing and he has some strikeout issues driven by a rather indiscriminate approach, but he has a chance to be the larger half of a corner outfield platoon.

Espinal is built like a human sports car, chiseled and square-shouldered. He runs like one, too, and may be a plus defender in center field at peak. He has crude feel for slasher-style contact right now, and the way his style and quality of contact develop will dictate what kind of role he’s capable of playing. Right now, he swings and hits like a tweener, but he’s so young that his physical abilities, which are loud, matter much more at this stage. He’s a talented, long-term developmental piece.

Green was a 14th-round senior sign last year and like most senior signs, had 45/50 stuff in college. He was 90-94 with two average breaking balls and had little college experience because he didn’t move into the rotation until his senior season. Last spring, Green’s stuff was up — touching 96 with big sink (he had a 67% GB%), and flashing plus secondaries — for a while before coming back to Earth during the summer after he returned from biceps tendinitis. He projects as a sinkerballing fifth starter.

Widener’s stuff was down across the board last year. Less velo, less spin. That, plus Reno’s hitting environment, plus the new Triple-A baseball, meant Widener went from being the minor league strikeout leader in 2018 to getting shelled in 2019 (his ERA was 8.10). His fastball has natural cut, which is something teams try to eliminate nowadays. It’s possible his fastball movement will change in a meaningful way, but for now we have him projected as a fifth starter.

Nelson had injury issues and moved back and forth from the rotation to the bullpen at Oregon. In the ‘pen, he sits upper-90s with life and angle, and his breaking stuff has nasty, vertical action. Reports we have from amateur scouts, when compared to what we have from Nelson’s pro summer, indicate the D-backs are perhaps trying to tweak Nelson’s breaking ball in some way. This is a potential late-inning arm but we wouldn’t anticipate Nelson to come along quickly considering how raw he is due to a lack of reps.

Smith has had elite strikeout-to-walk ratios dating back to college, but lacks the raw power and lift necessary to profile as an everyday first baseman. Last year, his body and mobility improved, which made him more playable in both outfield corners, and Smith had a strong offensive season in the Southern League, which is tough on offense. He now projects as a high-probability corner platoon role player.

There’s a chance Leyba hits enough to become a César Hernández type of low-end regular, and perhaps with his ability to play a passable shortstop, he’ll be something slightly better. But his injury history is lengthy (Arizona was granted a fourth option year on him due to injury), and he has a somewhat concerning lack of power. He’ll either hit enough to play everyday or he’ll need to start playing other positions to carve out a bench role. He’ll compete with Josh Rojas and Andy Young for playing time in the spring.

Barrosa isn’t toolsy but he has good feel to hit from both sides of the plate and terrific defensive instincts in center field. He’s stout and not very projectable, but already looks like a potential bench outfield type who can play all three spots, and it’s possible he develops an impact hit tool and finds a way to start somehow.

He’s not especially athletic and has mobility issues at third base, but Kennedy can hit. He’s tough to beat in the zone and has strength-driven doubles power, which is probably what he’ll max out with since the cement on the body appears dry. He’s got a squatty, catcherly build and some of the industry wants to see him back there. Arizona seems inclined to try at least some defensive variation here, as evidenced by Kennedy’s handful of starts at second base. We couldn’t find anyone who’s seen him play there, but we suspect he’d have a better shot at catching.

Reports from a couple of sources who saw Guzman in the DR during the summer were concerning. They described an elite athlete with an elite frame who had no idea how to hit, both from a swing efficacy and pitch recognition standpoint. That Guzman was passed over for a late-summer promotion to the U.S. is also telling. He’s too physically gifted to come off of entirely, but his first pro summer was erratic.

There are some yellow flags here. Alvarez didn’t pitch much during the summer due to minor injury, his build is somewhat soft, and he has a violent delivery that creates significant relief risk. He also has promising arm strength for his age, a dandy splitter (with an average spin rate under 1,000 rpm), and he creates viable shape and depth on his breaking ball, though it’s clearly behind his split. He’s likely a long-term bullpen piece, but he could have two huge out-pitches if the velo ticks up out of the bullpen.

Ellis has a very quiet, easy swing but somehow still generates plus power. His near-elite walk rate belies what scouts and in-office sources have indicated to be middling pitch recognition, which sometimes causes him to mis-hit crushable pitches. This manifests as lots of awkward or checked swings, but Ellis doesn’t typically flail and whiff, and he’s strong enough that the contact has a chance to be meaningful even if he didn’t take a great cut. It’s a fair, power-over-hit corner profile that takes a hit if Ellis should ever need to move to first base. So far he’s been playable, but not impactful, at third.

This is probably a right-hitting first baseman in the end, and Castillo’s frame is not as projectable as his measurables might indicate, but he’s young, already has sizable raw thump, and is quite athletic for how big he is. He’s also shown all-fields, in-game power and has surprising straight-line speed for his size. He’s clearly a tier below the Luken Baker type of high school hitter (which would be a 40+ or 45 FV type of prospect), but better than the heavy-footed mashers who beat up on their smaller peers in the lower minors.

A tooled-up ball of clay, Hill needs to be sculpted by player development. He is ultra-twitchy, has plus bat speed and surprising opposite-field power, and can absolutely fly, but he’s raw as a hitter and defender. They’ll try him at second base but the outfield is a long-term possibility.

Ginkel’s velocity has exploded since college, and he now sits 93-96 with tough angle. He also has two good secondaries, a change and slider that both have late, downward movement. His slider has sharp, vertical action and he’s pretty good at locating it down and to his glove side. He’s a likely long-term bullpen piece and he’d be a 40 FV if he weren’t already 26.

Mieses displays impressive flexibility and rotation in his shoulder and upper back, which helps enable his fastball to peak in the mid-90s. His delivery has some stop and start elements that can disrupt his timing and release point, which creates reliever risk, but the three-pitch mix has projection commensurate with a No. 4/5 starter.

Peacock has a heavy, low-90s sinker that has enabled him to generate a 68% groundball rate in 2019. His slider has a 2800 rpm spin rate, but visual evaluations of that pitch put it closer to average. His changeup moves and tails, but is often easy to identify out of his hand due to altered release/arm speed. On one level, Peacock is a one-pitch 25-year-old, but on another, he has a dominant, grounder-inducing fastball and his secondaries have some characteristics that may just need to be refined for one or both of them to be effective.

Mercer was a max-effort 94-97 in college, had scattershot fastball command, and a plus changeup. His velo was down in 2019 (we have him peaking at 96 but average 91-92) and neither of his two breaking balls is especially sharp, though they do have vertical action. We think he’s a Tyler Clippard-style changeup reliever so long as the velocity returns.

Grammes was a two-way player at Xavier (he has plus raw power) and we hope the focus on pitching will enable him to eventually have usable control. You could argue he has 20 control/command right now, and despite the electric quality of his stuff, he’s a long shot to be a big leaguer. But he was up to 99 in college and would flash an occasional 70-grade slider, so if things come together, he could be a bullpen monster.

In the last year or so the D-backs have tried more former position players on the mound than most all of the orgs we monitor in Arizona, and Herrera is one such player. He signed as a catcher, then quickly moved to third, and finally to the mound in his third pro season. His fastball was 94-97 almost immediately. The D-backs sent him right to the Northwest League despite erratic command and breaking ball quality. He’s a developmental relief prospect with premium arm strength.

McCarthy has gone from a player whose pre-draft physical talent may have been masked by injury to someone who appears to be injury-prone. He was running well in the Fall League but the quality of his contact was still limited despite his return from a pair of summer injuries, and we think he lacks the thump to be a real platoon option. It’s possible he has some yet-to-come physicality, which is why he’s still on the list.

The physical manifestation of a Henry Winkler catchphrase, Ay is an interesting 2019 sleeper who missed almost all of his 2018 college season due to injury, and generally threw few innings in college. He has a fast, efficient arm action and can spin a breaking ball. He might break out on a pro development program.

Tunnell played the middle infield at Baylor and didn’t step on a mound until after the D-backs signed him as an undrafted free agent in 2016. As you might expect, he’s raw for a 25-year old, but Tunnell has only recently developed real stuff. He was topping out at 92 mph during some of his 2018 outings, but now sits 93-96 with premium spin and a ball axis that creates vertical movement. He’s older, but might get a look in the big league bullpen sometime in 2020.

Diaz has a collection of average tools that are undercut by a haphazard approach at the plate. The power output that made him rather intriguing back in 2017 now seems like a synthetic creation of the Pioneer League hitting environment.

Short is a relatively unprojectable pitchability lefty with a vertical arm slot. Based on some of the other pro and amateur acquisitions the D-backs have made, some combination of this type of arm slot, the spin direction it helps create, and the approach angle of the pitch seem to be important to them. Short got a $922,500 bonus to sign instead of heading to Louisville.

2019 was the first year in pro ball for the 23-year-old Soto, and we don’t know why or where he came from. MiLB.com’s player page doesn’t even have his signing date in their transaction log. This is a pretty wild 23-year-old in the DSL, but Soto’s lean, athletic build, his arm strength, and his ability to spin a breaking ball are such that he needs to be on our radar, especially considering how little he has pitched.