Seattle Mariners Top 31 Prospects
Below is an analysis of the prospects in the farm system of the Seattle Mariners. Scouting reports were compiled with information provided by industry sources as well as my own observations. This is the second year we’re delineating between two anticipated relief roles, the abbreviations for which you’ll see in the “position” column below: MIRP for multi-inning relief pitchers, and SIRP for single-inning relief pitchers.
A quick overview of what FV (Future Value) means can be found here. A much deeper overview can be found here.
All of the numbered prospects below also appear on The Board, a resource the site offers featuring sortable scouting information for every organization. It has more details than this article and integrates every team’s list so readers can compare prospects across farm systems. It can be found here.
Rk | Name | Age | Highest Level | Position | ETA | FV |
---|---|---|---|---|---|---|
1 | Julio Rodríguez | 21.4 | MLB | CF | 2022 | 65 |
2 | Noelvi Marte | 20.6 | A+ | SS | 2023 | 60 |
3 | George Kirby | 24.3 | MLB | SP | 2022 | 55 |
4 | Matt Brash | 24.0 | MLB | SP | 2022 | 50 |
5 | Harry Ford | 19.2 | A | C | 2026 | 45+ |
6 | Emerson Hancock | 23.0 | AA | SP | 2023 | 45 |
7 | Edwin Arroyo | 18.7 | A | SS | 2026 | 40+ |
8 | Lazaro Montes | 17.6 | R | RF | 2027 | 40+ |
9 | Bryce Miller | 23.7 | A+ | MIRP | 2025 | 40+ |
10 | Adam Macko | 21.4 | A+ | SP | 2024 | 40+ |
11 | Taylor Dollard | 23.2 | AA | SP | 2024 | 40 |
12 | Alberto Rodriguez | 21.6 | A+ | RF | 2024 | 40 |
13 | Travis Kuhn | 24.0 | AAA | SIRP | 2022 | 40 |
14 | Levi Stoudt | 24.4 | AA | MIRP | 2023 | 40 |
15 | Gabriel Gonzalez | 18.4 | R | RF | 2026 | 40 |
16 | Jonatan Clase | 20.0 | A | CF | 2024 | 40 |
17 | Michael Morales | 19.8 | A | SP | 2026 | 40 |
18 | Juan Then | 22.3 | A+ | SIRP | 2022 | 40 |
19 | Prelander Berroa | 22.1 | A+ | SIRP | 2023 | 35+ |
20 | Spencer Packard | 24.6 | A+ | LF | 2025 | 35+ |
21 | Penn Murfee | 28.0 | MLB | SIRP | 2022 | 35+ |
22 | Cade Marlowe | 24.9 | AAA | CF | 2023 | 35+ |
23 | Jimmy Joyce | 23.3 | A+ | SIRP | 2025 | 35+ |
24 | Zach DeLoach | 23.7 | AA | RF | 2024 | 35+ |
25 | Riley O’Brien | 27.3 | MLB | SIRP | 2022 | 35+ |
26 | William Fleming | 23.2 | A | SP | 2025 | 35+ |
27 | Charlie Welch | 22.3 | A+ | C | 2026 | 35+ |
28 | Yeury Tatiz | 21.5 | A | SIRP | 2024 | 35+ |
29 | Kaden Polcovich | 23.2 | AA | 2B | 2024 | 35+ |
30 | Natanael Garabitos | 21.8 | A | SIRP | 2024 | 35+ |
31 | Bryan Woo | 22.3 | R | SIRP | 2025 | 35+ |
Other Prospects of Note
Grouped by type and listed in order of preference within each category.
On the Complex
Michael Arroyo, SS
Milkar Perez, 3B
Martin Gonzalez, SS
Edryn Rodriguez, SS
Victor Labrada, CF
Starlin Aguilar, DH
George Feliz, RF
This group is either currently in extended spring training down in Arizona or still in the Dominican Republic. Most of the players in this subgroup have also already filled out quite a bit. Arroyo (in the DR) is a skills-over-tools Colombian middle infield prospect with a maxed out frame and advanced feel to hit. Perez, 20, had a good 2021 on paper but lacks great feel to hit and may have given up switch hitting already, as he’s been seen taking right-handed at-bats against righties on the complex. He looked like an advanced, young, switch-hitting infielder during parts of last year, but it’s been a rough look so far in 2022. Gonzalez is the other relatively projectable prospect here, a collection of 40s and 50s with a chance to grow into more than that. Rodriguez, 19, had huge numbers in the 2021 DSL but is another maxed-out, skills-over-tools infielder who’ll have to prove it at each level. Labrada, 22, is a 70-grade runner who plays really hard, but he’s striking out a ton and there was no external scout support for him. Aguilar was a big dollar international signee a couple of years ago who is at risk of ending up a DH-only prospect because of the way he’s trended athletically. Feliz is similar to Gonzalez, except with a corner outfield profile.
Bench Ceilings
Robert Perez, 1B
Marcus Wilson, CF
Ben Ramirez, 3B
Axel Sanchez, SS
Perez generated some of the bigger peak exit velos in the org in 2021 and is pretty athletic in the box for a first base-only guy. He was sent back to Low-A after spending all year there in 2021. He could conceivably be a power-hitting bench option in the Ryan McBroom mold but is more likely a candidate for pro ball in Asia. Wilson can play center field and he has some power, but he strikes out too much to be a consistent big league option. Ramirez had a big time profile in high school as a projectable SoCal shortstop headed to USC. He didn’t hit for meaningful power in college. He has a strapping 6-foot-3 frame and can pick it at third base. Sanchez is all projection, a 19-year-old infielder with a glove-first toolkit for now.
Is There Enough Velo?
Joseph Hernandez, RHP
Leon Hunter, RHP
Isaiah Campbell, RHP
Devin Sweet, RHP
Juan Pinto, LHP
Sam Carlson, RHP
Hernandez, 22, is a funky, low-slot righty whose slider is death to right-handed hitters. He was living in the low-90s during the spring of 2022 and touching 94 mph, though it was during an early morning intrasquad; there might be more in the tank. Hunter, 25, is a super loose 250-pound reliever with big carry on a 90-91 mph fastball. Campbell, 24, was sent back to High-A to start the year. He was a reliable pitchability guy at Arkansas and dealt with some injuries there. He looked like a No. 4/5 starter at his best but more like an emergency spot starter more recently. Sweet was on the main part of the list in the past with the hope he’d find more velo in the bullpen to pair with his plus changeup, but he’s still sitting about 92 mph. Pinto, 17, was a high-profile 2021 signee who looked like he had filled out without adding any velocity, sitting about 87 mph during that same early morning intrasquad. Carlson sat about 90 mph the two inning he threw at Modesto before list publication; it’s fine to move on now.
System Overview
This is an extremely top-heavy system that has been able to actualize its high-profile prospects into big leaguers at a high rate. While we’re still waiting on some of them to be good big leaguers, the fact that this will still be one of our higher-ranked farm systems even after Jarred Kelenic, Logan Gilbert, Cal Raleigh, Kyle Lewis and others have graduated in the last two seasons is encouraging, even though Seattle lacks great prospect depth.
The Mariners’ ability to develop pitching is the org’s core competency right now. The shining example of this is obviously Matt Brash, who the Mariners traded for after he had barely thrown a pro pitch. They saw something San Diego didn’t (the same is true for me — I called Brash a “developmental relief prospect” at the time of the deal) and turned him into a monster. There are also lower-round draft picks spread throughout this list. Both the amateur and pro departments seem to be interfacing with the dev group well enough to hand them pitchers who are candidates for meaningful tweaks.
Seattle’s last couple of international amateur classes not been great upon their initial entry into pro ball. The team made changes to the top of their international scouting department at the end of 2018, a group that had been led by Tim Kissner and oversaw the signings of Julio Rodríguez, Noelvi Marte, Juan Then, and a lot of other players who were traded to other clubs while they were prospects, most notably Freddy Peralta. It’s possible that group had some hand in agreeing to deals with the players who Seattle would sign in the next couple of classes, and because of how the international market works, there is always a lag between when a new group gets its footing and when the players they target actually sign and begin low-level play in the states. But part of the reason this system is short on depth is because the early returns from the recent couple of classes aren’t that good.
Obviously a big part of it is also that Seattle traded two prospects who would have been in the 45 FV tier or above (Brandon Williamson and Connor Phillips) to add Jesse Winker and Eugenio Suárez to the fold just before the season. There are 10 prospects on other teams’ lists who were originally drafted or signed by Seattle, most of them guys who have turned into 40 FV backend starter or relief types, like Tommy Romero and JP Sears.
Is there enough ammunition to make another trade? The team’s 40-man starting pitching depth is thin and the Mariners aren’t in a position to withstand the typical rate of pitcher injury given the current state of their roster, especially as they seem committed to Brash, Justus Sheffield, and Riley O’Brien as relievers. They have viable spot starters in Tommy Milone and Darren McCaughan at Tacoma, but most teams need 10 or so starters throughout a season. It’s possible they will need to add depth, or might be motivated to improve on their current group (sorry, I know everyone loves Marco Gonzales), and have to do so with a trade. If last year’s deadline is any indication, in a blockbuster deal for a huge name, teams are going to ask for at least one of the 50+ FV guys, and because moving any of the others means taking from your current big league group, that makes Marte the more likely arm-twisting target for opposing teams. Unless several of the players in the 45 and 40+ FV tiers have huge breakouts, a more modest trade is much more likely.
Eric Longenhagen is from Catasauqua, PA and currently lives in Tempe, AZ. He spent four years working for the Phillies Triple-A affiliate, two with Baseball Info Solutions and two contributing to prospect coverage at ESPN.com. Previous work can also be found at Sports On Earth, CrashburnAlley and Prospect Insider.
One of the funny things about this list coming out so late is that Julio Rodriguez’s scouting report already looks a bit dated. He looks like at minimum a 50 in CF (OAA loves him even more than that, I’m not sure I buy it) and after a horrible start he’s turned it on and looks fantastic.
Pretty much anyone with five tools and is tall and plays the outfield gets comped to Dave Winfield, but Winfield was far more cautious at the plate. Rodriguez reminds me a lot of Andre Dawson, although obviously you can’t have Dawson’s career without insane longevity which is no guarantee (seriously, 10K PAs is a lot for anyone no matter talent level). I think he’s got potentially three or four 6-win seasons in him, but he’s going to get there as a pretty free swinger. Not anything like, say, Avisail Garcia or Tim Anderson, but he’s probably a bit more free swinging than average.
Thing that’s off is his run grade more than anything, it’s easy 70 speed at the present, and it’s closer to a 80 than a 60.
This is probably also why he’s also doing better in CF than expected.
Sprint speed is 29.8, which is top 10 in the league. His HP to 1B is only 4.25, though, which is 26th. Either way, he’s comfortably ahead of a bunch of other people who we think of as having elite speed like Victor Robles, Adolis Garcia, and Luis Robert (who must have lost some speed when he bulked up–he’s 2.5 seconds behind Rodriguez). A 70 sounds about right.
Yea per statcast he has the 6th highest average sprint speed.
Weirdly enough, #1 is Bobby Witt, who also has a 60 speed grade here
Dawson’s a super comp – I was thinking that Rodriguez has a lot of Javy Baez in him at this moment on offense, but his ability to look like a no-brainer CF had me scrambling for a Heyward/Gallo type for his defensive profile. Dawson is exactly that guy.
The one caveat to this comp, and I’m glad Eric expounded on this a bit – it’s downright rare, and surely an 11 on a 1-to-10 scale of difficulty, for a college-aged prospect to improve his numbers across the board after being promoted mid-season within the upper half of the minors. When I see that a young player has done something like this, it sets off bells in my head that the kid is almost toying with baseball at that level, which in turn means we might be talking about a generational prodigy here. Because of that possibility, and Rodriguez’s makeup and work ethic, I can’t rule out the possibility that he overcomes his swing-and-miss proclivity by his third or fourth MLB season, much like Mike Schmidt did. If that scenario plays out, along with the good health to ensure longevity, then we can upgrade from a replay of Dawson’s career to a replay of Schmidt’s career (only with the Gold Gloves coming in right field instead of third base.)
Can’t believe it just dawned on me, but after factoring everything above, the best 21st century comp for Rodriguez is George Springer.
More precisely:
George Springer, but with a 3-year head start.