Prospect Report: Diamondbacks 2023 Imminent Big Leaguers

Just seven games into his 2021 minor league season, Carroll sustained a posterior capsular avulsion fracture and a labrum tear during a swing on which he homered. The rip was more explosive than his shoulder could handle, and part of it tore away from the bone. He spent most of the rest of the year rehabbing in Arizona, often attending Diamondbacks games in his sling. This isn’t a common injury and the industry wasn’t quite sure what to make of its impact on his trajectory. There was some worry that Carroll wouldn’t be quite the same player when he returned, but he quickly allayed those concerns by dominating the upper minors as soon as the 2022 starter pistol fired, notching an amazing 53 extra-base hits in just 91 Double- and Triple-A games before he slashed .260/.330/.500 during a September big league call-up.

Carroll has evolved in some surprising ways as a hitter. His amateur look was that of a slash-and-dash leadoff man with doubles power and a great idea of the strike zone. While some of those skills are still bricks in Carroll’s baseball-playing foundation, he has developed much more power than even the most optimistic amateur projections. His forearms have grown like the Grinch’s heart, and Carroll can now bang wall-threatening contact to all fields with the flick of his wrists. The compact nature of Carroll’s body and swing gives him a little extra time and distance to diagnose pitches, and his strength makes him a threat to do damage on the ones that he lets travel deep into the hitting zone. He rarely chases and spoils lots of well-executed pitches, grinding away at opposing pitchers. Because Carroll runs such deep counts, his strikeout rates have been higher than one might expect given his reputation as a plus contact hitter. He did show some swing-and-miss vulnerability at the top of the strike zone throughout 2022, but seemed to be remedying that toward the end of the season. He’s a complete hitter who will likely produce some 25-30 home run seasons by virtue of his contact quality and frequency, and some .400-plus OBP seasons because of his plate discipline and speed. And Carroll can really motor: he’s a no-doubt 80 runner and routinely posts sub-4.00 second times to first base. His speed makes him a defensive fit in center field but a lack of arm strength and the presence of young Alek Thomas in Arizona will likely push Carroll to left, where he might be the game’s best defender at that position. Poised to make an immediate impact as Arizona’s leadoff hitter, Carroll is the tip of the spear the Diamondbacks are pointing at the Dodgers and Padres.

Jones’ combination of present baseball ability and physical projection were unmatched in the 2022 draft class. At age 14, thin as a rail, he was already hitting balls out of big league spring training stadiums during workouts. Now he’s a strapping 6-foot-4 and has grown into considerable power, all while maintaining some amount of future physical projection (i.e. there is going to be more power here) and impact, up-the-middle defensive ability. While he’s taken groundballs at shortstop in the past and is arguably athletic enough to develop there in pro ball, Jones is such a savant in center field that scouts won’t typically entertain that notion; he projects as a 70-grade defensive center fielder. His first step can be a little delayed, but Jones’ huge strides eat up tons of ground in the outfield, and he gallivants into the gaps, robs would-be doubles, and has a runner-sniping arm.

Jones’ swing isn’t quite dialed in. He tends to bar his front arm and load his hands high, which made it impossible for him to turn on velocity on the showcase circuit when he was facing better, faster pitching than he did during varsity play. Over the course of two years worth of showcase play tracked by Synergy Sports, amounting to roughly 250 swings on tape, Jones never pulled a ball to the left of the left-center field gap, and all but about a dozen of his airborne balls in play were to right field. This is a little odd, but it might be remedied with an unobtrusive mechanical tweak.

Everything else Jones shows you in the batter’s box is exciting. He’s a plus rotational athlete, his hands are exceptionally strong, he can drive his top hand through contact to punish pitches at the top of the zone and he sometimes alters his footwork and the bend in his lower half to dip down and barrel low pitches. Even though his stride is relatively conservative, he is still generating so much force with his legs that his back foot will sometimes come completely off the ground as he’s making contact, à la Bryce Harper. Nitpicking about his swing actualization is fine because we’re talking about one of baseball’s best prospects, but the foundation of present skills and tools combined with Jones’ physical projection makes him a potential franchise-altering superstar.

Just three days after signing, Jones suffered a left posterior labral tear while hitting, another glitch in the Matrix that seems to be causing every high-profile Diamondbacks prospect to suffer a severe shoulder injury. Jones had surgery, missed the back half of the summer and instructs, and only began hitting again in January. The injury adds more volatility to a profile that already had some and might cause Jones to open 2023 in extended spring training, but it’s encouraging that Jordan Lawlar returned to normal after enduring a similar injury.

A complete prospect and a total baseball rat, Lawlar had been a touted amateur as an underclassman and held serve as a near top-of-the-class talent for two or three years, even amid the volatility of the 2020 draft process. He has continued on that path as a pro, slashing an incredible .305/.402/.510 so far in the minors, reaching Double-A and the Arizona Fall League at age 20 after he had torn his labrum the year before. Some of Lawlar’s offensive performance has been inflated by his home park’s hitting environments, especially Low-A Visalia and Double-A Amarillo. Arizona’s relatively new Amarillo affiliate is especially extreme relative to the rest of the Texas League. So Lawlar isn’t quite as good as his cartoonish stats — his present hit/power combination is actually closer to average — but he does everything well and is a potential plus defender at short because of his acrobatics.

Lawlar’s throwing stroke to first base can sometimes be a little odd, but he finds all kinds of crazy ways to contort his body and send the baseball where it needs to go, which is especially true of his feeds to second base. If he develops into a plus shortstop defender with a well-rounded offensive game, he’ll easily be an impact big leaguer, and probably soon. Lawlar’s hit tool projection is a bit of a conundrum. There are aspects of his swing that are very exciting and consistent with great big league hitters (his raw power and bat speed are uncommon for a shortstop, while his bent-at-the-waist hitting posture is akin to Mike Trout’s and Dylan Crews’), but his bat path is fairly grooved, and here the projection is that when the cement dries on Lawlar’s hit tool, it will be a little south of average. He’s still likely to get to enough power and play good enough defense to be an impact regular for Arizona.

The Diamondbacks selected Pfaadt with their final pick in 2020’s abbreviated draft. The righty had only made 11 career starts at then-Division-II Bellarmine University, but a successful 2019 summer on the Cape and a lights out draft spring suggested that he was a real prospect. He rocketed through Arizona’s system in 2021, making brief stops at both A-ball levels before closing the season with six starts for Double-A Amarillo, where he then spent most of 2022 dominating to the tune of a 32% K% and 4% BB% before a late promotion to Reno.

Tall, well-built, and athletic, Pfaadt has plenty of starter traits. He has a loose arm, a frame built for eating innings, and a repeatable delivery. He sits 92-95 mph while touching higher with his carrying four-seam fastball, and like any good D-backs prospect, moves it well north-south while generating whiffs at the top of the zone; he also has a sinker as a change of pace. His best offspeed is a plus slider, a tight, two-plane offering in the low-to-mid-80s. The curve features similar movement with longer break and both are nasty when he runs them off the plate glove side, though both play in the strike zone, as well. Pfaadt’s fading change flashes bat-missing action, but it also flattens at times, and even though Pfaadt is comfortable enough to use it against righties, it’s the pitch he has the least consistent feel for locating. While some of the org’s other high-profile names have had developmental hiccups, Pfaadt has knifed through Arizona’s system without issue and is now a mid-rotation starter prospect on the doorstep of the big leagues.

Jameson reached the majors in 2022 and is ready for prime time. He ran a 6.95 ERA in Triple-A throughout 2022 but the hitting environment in Reno isn’t fair to pitchers, and Jameson’s stuff, control, and athleticism are all on par with a good team’s fourth starter. Jameson sits 95-96 mph, touches 99, can add and subtract sink from his fastball, and his mid-80s slider is comfortably plus. A slower curveball and occasional mid-80s changeup give Jameson the weapons to work through a lineup multiple times even though they’re just fair. While his delivery features a lot of effort, he has held velocity like this across a starter’s workload every year since he was drafted. He lacks precise command, but he throws enough strikes to start and bully hitters with his velocity and slider for five and six innings at a time. Jameson is also a extremely competitive and has the makeup for a late-inning role should he eventually have to make way for some of Arizona’s other good young starters.

Nelson spent most of his college career in the bullpen showing huge stuff, fringe command, and repertoire depth that led to optimism surrounding his development as a starter. He also dealt with an eye condition that would later require surgery to strengthen the collagen fibers within his cornea, surgery he had in 2020 while he also reworked his mechanics. Then Nelson had a dominant 2021 season spent mostly at Double-A Amarillo, striking out 163 hitters in 116.1 innings, all as a starter. His numbers backed up in 2022, but that’s typical of pitchers who go to work in Reno. Perhaps of real concern was Nelson’s velocity, which has fluctuated a few times during his career and was down for most of 2022. By the time he was called up to Arizona in September, it was back into the mid-90s with Nelson’s trademark angle and carry. He tends to live in the tempting upper third of the strike zone and above, where his heater is almost impossible to hit due to its riding life. Nelson used his fastball about 65% of the time in 2021 and 61% in 2022, both at the upper boundary of what is typical for a big league starter. He tends to throw his two breaking balls (his curveball’s shape pairs especially nicely with his fastball) in the zone, often early in counts, and then use the fastball as a finishing pitch. The fluctuations in velocity, Nelson’s mechanical look, and his end-of-year scapula injury in 2022 wrap his profile in long-term relief risk, but that’s pretty standard among big stuff pitchers toward the back of the top 100. He is otherwise a major league-ready fourth starter.

Walston was a young-for-the-draft pop-up arm who made a rapid ascent up teams’ boards during his senior spring. He was a very projectable lefty with lovely natural curveball shape and what seemed like burgeoning velocity. He also had feel for a changeup (which is now arguably his best pitch), precocious command, and a fastball with life that enabled it to compete for swings and misses in the zone even though it wasn’t all that hard. As he’s climbed the minors, Walston has shown flashes of more heat here and there during instructs and backfield activity, peaking in the mid-90s but never sustaining that velo for long stretches. Instead he tends to sit in the 91-93 mph range, which is where Walston’s fastball was again in his first spring start of 2023.

He’s managed to strike out more than a batter per inning up through Double-A because of the quality of his secondary stuff. Walston mixes in two distinct breaking balls — a low-80s slider and a mid-70s breaking ball — and his mid-80s changeup to get by. He’ll throw his curveball for strike one, and he’s unpredictable against right-handed hitters with two strikes because he’ll turn over the changeup and back foot his slider against them. It is likely that his fastball will be quite vulnerable against big league hitters unless Walston somehow throws harder. He’s not yet 22 but, since his brand of athleticism has more to do with body control for his size than exciting rotational movement, he’s not the sort of athlete who seems likely to come into late-blooming velo. It’s possible Walston will debut at some point in 2023 (probably toward the end of the year if so), but he’s more likely to exhaust rookie eligibility in 2024 and establish himself as the Diamondbacks’ no. 4/5 starter in 2025.

Barrosa was added to Arizona’s 40-man in the offseason after slashing .276/.374/.438 at Amarillo. His power production (12 homers, as many as he had in his entire career up to that point) was caricatured by the offensive environment at that affiliate, but Barrosa has plus bat-to-ball skills from both sides of the plate and can really go get it in center field. This is a slash-and-dash style hitter who sprays light contact all over the place. He makes in-flight adjustments to breaking balls, is naturally short to elevated fastballs, and can get deep into his legs to dip and impact pitches in the lower third. While his somewhat elaborate footwork can sometimes disrupt his timing, it’s essential to Barrosa winding up his body and swinging hard, and his stroke is otherwise short, direct, and flat, which is conducive to making contact all over the zone. From the left side, the momentum of Barrosa’s swing naturally carries him toward first, and he can get down the line in under 4.10 seconds. He is also an excellent defensive center fielder and especially good at breaking on balls hit over his head. He doesn’t have the pop of an everyday guy, but Barrosa’s ability to put the ball in play from both sides of the plate and play great outfield defense should make him an important complementary player.

Martinez was working in the upper 90s before his 18th birthday, but command, fastball shape, and the lack of a true plus secondary pitch marred his early-career performance. So, too, did injury. Martinez had Tommy John in 2021, which put him in a bit of a developmental bind since he came back in the middle of 2022, his 40-man evaluation year, and only had a couple months to earn a roster spot. He did. After moving to the bullpen post-surgery, Martinez saw his velo leap into the 97-100 mph range, and a brand new splitter not only gave him a plus secondary weapon, but the pitch might end up being even better than that. It comes out of his hand with bullet spin (but barely any spin at all), which sometimes makes it look like a slider when it finishes to his glove-side, but often it just has bat-missing sink. There are even times when Martinez will mis-release his splitter and it accidentally tails back over the glove-side corner of the plate, freezing hitters. There is still an actual slider here (83-86 mph) and it still isn’t great, but the 100-mph fastball and the splitter should both be enough for Martinez to work in the later innings of big league games assuming he ends up with at least 40-grade command as he continues to shake off the rust post-op. The Diamondbacks bullpen was really bad in 2022 and while they’ve improved it significantly through various signings, there’s a pathway to the 2023 closer role for Martinez if he throws enough strikes.

Fletcher was a tweener SoCal high school prospect who matriculated to Arkansas, where he developed in unexpected ways. First, he filled out and added more power than was expected of his 5-foot-9 frame. He also chased more than anticipated at Arkansas and early on in pro ball, which inflated his strikeout rate in the latter setting. As Fletcher has traversed the minors, his K rates have stabilized in the teens and his underlying contact data (88% Z-contact, 71% overall contact%) was very strong in 2022. The sweeping nature of Fletcher’s swing (which is geared for low-ball contact) and his persistent propensity to chase perhaps make this feel less stable than is typical of a 25-year-old with such a long track record of hitting. Fletcher is an average runner from home to first, but his routes in center field are direct and polished. He’s fine out there, so even though this is a tepid projection for his bat, there’s still a solid fifth outfielder’s skill set here.

Peak Vargas will sit 97-101 mph with huge riding life and a plus slider. Even as he’s shortened what was once a very violent, Kimbrel-esque arm action, Vargas has a hard time repeating his release and goes through stretches where he is extremely wild. Cleveland put him on the 40-man after the 2020 season, and Vargas ended up having Tommy John before his first spring on the roster had even concluded, causing him to miss all of 2021 and the start of 2022 to rehab. Part of a crowded bullpen field in Cleveland, and volatile-seeming due to his lost time and control issues, he was tough for the Guardians to keep after the 2022 slate. But for a Diamondbacks club in desperate need of bullpen upgrades, he presented an opportunity to acquire a hard-throwing 23-year-old with late-bloomer traits and hand him to Brent Strom. The big velo was there as soon as the 2023 starter pistol fired, with Vargas touching 101 in his first Cactus League outing. His lower half seems much more balanced throughout his delivery now compared to his LIDOM look during the 2022-23 winter, which might help him find a more consistent release. Vargas has two option years left, so if it turns out he’s still very wild, he’ll end up being a hard-throwing up/down reliever. But there’s more ceiling than that here if things click, and that’s baked into his FV.

Alexander really struggles to get on top of high fastballs, and even though his 2021 strikeout rate (32%) is anomalous when compared to the rest of his pro track record (23-25%), readers should still regard Alexander’s hit tool as role-limiting. He is, however, a viable defensive shortstop with a huge arm, and Alexander hits for enough power when he actually makes contact to be a viable, lower impact bench infielder.

Canzone has above-average pop from the left side and has kept his strikeout rates hovering around the 20% mark as he’s hit for power at Arizona’s upper-level affiliates. His hard-hit rate (40%) is a shade above the big league average, which is true of most of Canzone’s power-measuring underlying metrics, but his contact rates tend to be shade below (he’s a bit of a bucket strider and can open up too soon on stuff breaking away from him) and he’s a corner-only defender. The defensive component likely played a role in Arizona leaving Canzone off of their 40-man roster while they added Barrosa and Fletcher, as Canzone’s offensive ability is about the same as the latter’s. He still projects as an above-replacement corner platoon bat, probably one of relatively low impact because the power isn’t monstrous. The Diamondbacks outfield mix is very crowded and it’s perhaps more likely that Canzone is dealt somewhere with roster room for him if he performs at Triple-A Reno again.

Solomon had huge stuff in college, but strike-throwing issues and Notre Dame’s pitching depth pushed him into a multi-inning relief role. The Astros drafted and developed him in a piggyback starter role and by the time he had finished his first full season in pro ball, he had started as many games as he had his entire college career. He looked like another of Houston’s vertical fastball/breaking ball success stories when, in 2019, he blew out and needed Tommy John surgery. Deployed as a more traditional starter in 2021 and 2022, Solomon remained walk-prone and the Astros eventually designated him for assignment. The Pirates claimed him off waivers and quickly lost him to the Diamondbacks in the minor league phase of the 2022 Rule 5 draft. Back with former Astros pitching coach Brent Strom in Arizona and moved to the bullpen, Solomon has shown a velo spike out of the gates in 2023. Up from the 90-92 mph range, his fastball is again sitting 93-95 with vertical ride, and Solomon’s huge curveball flummoxes hitters on first blush. He isn’t on the 40-man right now, but he seems like a good bet to be up and down from Reno throughout 2023.

Rice looks like a nice ninth round find from 2021. He pitched two seasons at Gulf Coast State College and two at Presbyterian University, and then was a graduate transfer to Kennesaw State for the 2021 season. He sits 93 mph with flat angle that helps him garner whiffs in the strike zone, and Rice’s low-80s breaking ball has vertical depth that allows it to play as a bat-misser when he locates it, which comes and goes. He looks like a quick-moving up/down lefty relief piece.

Grammes would flash two 70-grade pitches in college in his upper-90s fastball and his slider, but he was so comically raw as a strike-thrower that he slid all the way to the fifth round of the 2019 draft. He played two ways at Xavier, and at the time, it seemed possible pro development might make his strike-throwing more consistent and enable him to work in a high-leverage bullpen role. That started to occur in the fall of 2020. Grammes’ body began to mature and he had better feel for release than he did while in school. He ditched his changeup for a second breaking ball, a nasty low-80s curveball. Grammes began the 2021 season with seven good starts, during which he threw strikes at a 40- or 45-grade rate, a shocking development for him if it wasn’t a small-sample aberration. Sadly, his UCL blew in June of 2021, he had Tommy John in early July, and he was quite wild when he returned from rehab in 2022. He’ll still show you mid-to-upper-90s heat and two good breaking balls, but his command is not where it needs to be for him to be relied on in a big league relief role. If that clicks, he’ll be a middle-inning weapon.