The best farm system in the American League has some superstar potential up top with improved depth in its lower tiers, especially in pitchers who have a chance to be something in the majors, even if they just turn into quality relievers, along with a wave of outfielders signed from Latin America who should provide this system’s next set of breakout prospects.
To qualify for these rankings, players must still be eligible for the Rookie of the Year Award in 2022, which means they may not have more than 130 at-bats, 50 innings pitched or 45 days on an active roster heading into this season.
1. Julio Rodríguez, OF (Top 100 ranking: No. 9)
Age: 21 | 6-3 | 180 pounds
Bats: Right | Throws: Right
Rodríguez is an offensive force, obliterating two levels last year at age 20, with high batting averages, patience and big power — enough that he could have at least gone to Triple A later in the season. The most impressive aspect of his pro career so far is how well he controls the strike zone, including making so much contact, despite long levers and a big swing. That swing is very easy, though, with good hip rotation and huge power to his pull side. He’s also shown the ability to go the other way for softer contact, a tremendous skill for a hitter who hadn’t shown anywhere near that advanced an approach before last season. Rodríguez is a 55 runner, if not a 60; and played some center this year, looking capable out there, although his size is going to lead him to a corner sooner rather than later. Rodríguez’s 2021 season answered a lot of questions about how good a hitter he was, and while there are still some adjustments to come as he faces pitchers who can better locate their offspeed stuff, he looks like a long-term cleanup hitter who’ll challenge for MVP awards with 30-40 homers, high OBPs and, at least, solid defense in right field.
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2. Noelvi Marte, SS (Top 100 ranking: No. 11)
Age: 20 | 6-1 | 181 pounds
Bats: Right | Throws: Right
Marte’s U.S. debut went rather well, as he hit .271/.368/.463 as a 19-year-old in Low A, tying for sixth among all Low-A hitters with 17 homers, while finishing in the top 15 at the level in both doubles and walks. Marte has a very easy swing with quick hands and already makes consistent, hard contact despite only turning 20 in October. He already has above-average game power and should end up firmly in the plus power range, with 25-plus homers a year in his peak, while he’s a plus runner who’s shown some aptitude for base stealing already. He’s a shortstop right now who could stay there if he doesn’t get too big, but might end up outgrowing the position and moving to third base, for which he already has the arm and hands to be a 55 or 60 defender. If he stays at short, he could be a top-five player in baseball with this combination of approach, power and speed, while even at third base he should end up among the best players at his position in the majors, and he’s probably no more than two years away from making his debut.
3. George Kirby, RHP (Top 100 ranking: No. 45)
Age: 24 | 6-4 | 215 pounds
Bats: Right | Throws: Right
Drafted: No. 20 in 2019
Kirby was the Mariners’ first-round pick in 2019 out of Elon College and had an impressive yet brief pro debut that summer in the short-season Northwest League, throwing 23 innings without walking a batter. He returned from the lost pandemic year with more velocity, working at 96-100 mph as a starter without any loss of command or control. He has a four-pitch mix, with the changeup his best secondary offering, but he doesn’t have great ability to spin the ball and the breaking pitches are both closer to average. Kirby only threw 65 innings in 2021, in part because he missed a month with a tired right shoulder, so there’s at least a small question of whether he can hold this plus-plus velocity for an entire season. He’s a likely mid-rotation starter, with a chance for more if the stuff ticks up and holds up for a normal workload.
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4. Harry Ford, C (Top 100 ranking: No. 49)
Age: 19 | 5-10 | 200 pounds
Bats: Right | Throws: Right
Drafted: No. 12 in 2021
Ford is an incredibly athletic kid who offers tantalizing upside on both sides of the ball, but also spurs wide divisions among scouts over whether he can even stay behind the plate. He’s a plus runner with elite bat speed, and has plus raw power with the projection to get to 70 or more. His bat can be in and out of the zone too quickly, however, which may limit his game power as he faces better pitching. Behind the plate, he’s a good enough athlete to work his way into becoming an average receiver and thrower, but despite that athleticism, he doesn’t move easily or flexibly enough to make that the most likely outcome given how far he has to go. His speed should let him move to any of several other positions, like third base, center field, or even right field at worst. There’s some risk in the bat as well, but the hit/power/speed upside would make him an above-average regular or more at any position.
5. Matt Brash, RHP (Just-missed list)
Age: 24 | 6-1 | 170 pounds
Bats: Right | Throws: Right
Drafted: No. 113 in 2019
Brash was the big breakout prospect in the Mariners’ system this year after coming to Seattle in an August 2020 trade that sent Taylor Williams to the Padres. Brash had just 5 1/3 pro innings before the deal, but blew up this year, punching out 142 guys in 97 innings between High A and Double A. He has electric stuff, mid-90s with spin and a wipeout slider, missing left- and right-handed bats at both levels. The delivery, though, is ugly. Brash has a head-whack, comes back across his body, and lands on a stiff front leg that forces him into a roundhouse-kick move at release, so it’s unsurprising that he’s had some injury issues in the past and has below-average control, walking 48 men last year. He’s more likely to be an impact reliever, but his ability to miss bats gives him a chance to succeed as a starter.
6. Brandon Williamson, LHP
Age: 24 | 6-6 | 210 pounds
Bats: Right | Throws: Left
Drafted: No. 59 in 2019
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Williamson is a big, sturdy left-hander with a four-pitch mix who gets solid extension thanks to his 6-foot-6 frame, making it a tough look on left-handed batters in particular. He’ll show plus velocity and a bucket of 55s in the rest of his arsenal, with fringy command right now that he gets around because he has multiple ways to get hitters out. He struck out 37.4 percent of batters he faced last year, third among all qualifying minor league pitchers, and had no trouble with right-handed hitters thanks to a solid average-to-55 changeup. It’s a smooth enough delivery for him to repeat and possibly get to average command, which would make him at least a mid-rotation starter with a chance to be a No. 2.
7. Emerson Hancock, RHP
Age: 23 | 6-4 | 213 pounds
Bats: Right | Throws: Right
Drafted: No. 6 in 2020
Hancock missed some time again in 2021, losing a month midyear and then sitting for the final five weeks, but it was nothing serious enough for surgery and the hope is he’ll be 100 percent again this spring. His velocity was down last year to 91-94 mph, perhaps due to whatever was ailing his arm, but he did find success with the changeup that the Mariners had him dust off after they drafted him — it’s a 55 if not better and he held lefties to a .147 OBP in 68 place appearances. His breaking stuff was fringy in college, but it’s flashed better in pro ball as well. The upside here is a true four-pitch guy with control and maybe two pluses among his offerings, but after he threw just 44 2/3 innings last year with reduced stuff we really have to see him healthy again to think in terms of ceiling.
8. Levi Stoudt, RHP
Age: 24 | 6-1 | 195 pounds
Bats: Right | Throws: Right
Drafted: No. 97 in 2019
Stoudt made his pro debut last year after rehabbing from 2019 Tommy John surgery, but his first season was interrupted by further forearm tightness, ending his year in late August. He’s been up to 97 mph with a plus changeup, crushing left-handed batters last year, along with a fringy breaker that has some depth on it thanks to his high arm slot. His arm action is short and he should be able to get to average control and probably average command in time. He still has back-end starter potential if his elbow is fully recovered, with the fastball/changeup combination good enough to at least get through an opposing lineup twice.
9. Jonatan Clase, OF
Age: 20 | 5-8 | 150 pounds
Bats: Left | Throws: Right
Clase only played 14 games in the Arizona Complex League last year due to injury, but the good news is that his body has started to fill out more, so there’s more power off the bat. He’s switch-hitting now, having batted left-handed since he signed even though he’s a natural right-handed hitter. He’s continued to put on muscle this offseason, so he’s probably more of a 60 runner now than 70 or 80, although he’s still a plus defender in center, and he was a perfect 16 for 16 on the bases last year — yes, stealing more than one base per game, and finishing third in the league despite playing only a quarter of its schedule.
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10. Gabriel Gonzalez, OF
Age: 18 | 5-10 | 165 pounds
Bats: Right | Throws: Right
The 17-year-old Gonzalez was one of the best performers in the Dominican Summer League in 2021, hitting .287/.371/.521, showing solid plate discipline and power while stealing nine bags in 12 attempts. He’s a hitter first, a potential 60 hit tool who should grow into above-average power, probably also growing out of center field but with the bat to profile well in a corner. He should make his U.S. debut this year in the Arizona Complex League.
11. Alberto Rodriguez, OF
Age: 21 | 5-11 | 180 pounds
Bats: Left | Throws: Left
Acquired from Toronto in 2020 for a month of Taijuan Walker, Rodriguez is a stocky right fielder who shows plus power and a plus arm, taking off after a horrible first month last year in Low A (he hit .325/.409/.532 until he was promoted to High A with a week to go). He’s an average runner who should be a 55 defender in right field, and if he continues to hit left-handed pitching he should be no worse than an everyday player, with 20+ homer upside.
12. Michael Morales, RHP
Age: 19 | 6-2 | 205 pounds
Bats: Right | Throws: Right
Drafted: No. 83 in 2021
Morales was the favorite of scouts who focus on deliveries in last year’s draft, but his velocity tapered off from 93-94 mph to 88-92 mph and below by the end of the spring. He has three pitches that all project to get to at least above-average as he fills out, with the potential for plus command given his clean delivery and high degree of coordination already for someone so young. The Mariners’ third-rounder from 2021 has No. 2 starter upside, but is probably a long-term project for player development.
13. Zach DeLoach, OF
Age: 23 | 6-1 | 205 pounds
Bats: Left | Throws: Right
Drafted: No. 43 in 2020
The Mariners’ second-round pick in 2020, DeLoach looks like a great extra outfielder, with strong on-base skills and fringy power in a corner, and the ability so far to hit left-handed pitching as well as right. His pitch recognition is good enough that he might be the rare corner bat who becomes a regular without 20-odd homer power.
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14. Edwin Arroyo, SS
Age: 18 | 6-0 | 175 pounds
Bats: Switch | Throws: Switch
Drafted: No. 48 in 2021
The Mariners’ second-round pick in 2021 grew up in Puerto Rico but moved to Florida for his draft year, although he returned to the island to play in the winter league this offseason and gain some more reps. He’s very likely to stay at shortstop and could end up plus there, while there’s wide disagreement on what he’ll be at the plate, with some scouts seeing future power but questioning the hit tool and others seeing a short swing that will produce contact but not power. He didn’t turn 18 until August, a month after the draft, which might explain some of the disagreements. I see multiple ways for him to develop into a regular.
15. Connor Phillips, RHP
Age: 21 | 6-2 | 190 pounds
Bats: Right | Throws: Right
Drafted: No. 64 in 2020
One of the Mariners’ two second-round picks in 2020, Phillips, who went to a two-year college in Texas, is a strong right-hander with power to everything he throws. Coming from a quick, high-effort delivery that he has a hard time repeating, he’ll show above-average velocity and good ride on his fastball along with a slider that’s trending toward plus. He walked more guys than you’d like last year, but it was also inconsistent — he had several outings late in the year where he started pounding the zone and had more across-the-board success. He doesn’t show a lot of touch-and-feel to his pitching, with a below-average changeup and no other real weapon to keep lefties off base, and missed some time midyear with an unspecified injury, all of which points to at least 50/50 odds he ends up in relief.
16. Juan Then, RHP
Age: 22 | 6-1 | 175 pounds
Bats: Right | Throws: Right
Then has been up to 99 mph in the past but his velocity backed up this year; he was 93-94 mph at points during the season and again in the Arizona Fall League, with an above-average changeup and fringy slider. He comes from a low 3/4 slot with some sling to it, which should give him some natural advantage against right-handers even without an average breaking ball. He was awful in 14 starts in High A last year, with a 6.46 ERA thanks to 12 homers and 68 hits allowed in 54 1/3 innings, and missed time twice with injuries despite never actually hitting the injured list. He might need to go to the bullpen at this point to regain his missing velocity and lost effectiveness.
17. Adam Macko, LHP
Age: 21 | 6-0 | 170 pounds
Bats: Left | Throws: Left
Drafted: No. 216 in 2019
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Macko struck out 36 percent of batters he faced last year in nine starts, but missed a month midsummer and then was shut down in early August with a non-structural shoulder injury. When healthy he’s bumping mid-90s with two above-average breaking balls, which I presume is why opposing teams barely let any left-handed batters even face him in 2021 — 85 percent of the batters he faced were right-handed — and makes his year a bit more impressive given how unfavorable that basket of hitters would be for him. He’s very likely a reliever but has a chance to be a high-leverage guy. He was born in Slovakia, then spent several years growing up in Ireland before moving to Alberta, where he finished high school. He has a chance to be the first Slovakian-Irish-Canadian big leaguer, although he always says he’s from Queens.
18. George Feliz, OF
Age: 19 | 5-11 | 160 pounds
Bats: Right | Throws: Right
Signed in 2019 for $900,000, Feliz is a wiry but strong center fielder with very quick hands at the plate, hitting for a good balance of average and power in the Dominican Summer League in his debut last summer. There might be some swing-and-miss here going forward, and he probably should have come over to the Arizona Complex League at some point — I’m sure he would have if we hadn’t lost 2020 to the pandemic — to face better pitching. He has everyday upside in center, maybe above-average if that hand speed translates into harder contact.
19. Cade Marlowe, OF
Age: 25 | 6-1 | 210 pounds
Bats: Left | Throws: Right
Drafted: No. 606 in 2019
Marlowe could be a Kole Calhoun-type player with more speed and less hit tool, able to play center with power but maybe a bit too much swing-and-miss to be quite as good as Calhoun at his peak. He hits the ball hard and is willing to go the other way, with plus power to pull that led to 26 homers and a .275/.368/.566 line across three levels last year. It’ll come down to contact — if he can cut down on his swing-and-miss a little, he could be a regular.
20. Milkar Perez, 3B
Age: 20 | 5-11 | 173 pounds
Bats: Right | Throws: Right
Perez is an above-average defender at third who has a good eye and contact skills, posting a .463 OBP at age 19 in the Arizona Complex League last year. He also hit a total of zero home runs in 51 games, because he has a super-wide setup with no stride or weight transfer and a very short, flat swing that is going to put the ball in play a lot without putting it very far. He seems like a great candidate for some kind of swing change, although he may also have to be willing to trade some of that contact-orientation in his approach to get to average power. If he can hit 15 homers a year, he’s a regular.
Others of note
Kaden Polcovich was great in High A in his pro debut last year but was obliterated by Double A pitching, hitting .133/.242/.211 in 36 games after his promotion. He has a great eye at the plate and plus speed, so despite his lack of a clear position he can fill in at multiple spots and also add value as a pinch hitter/runner. … Right-hander Sam Carlson returned to the mound three years and 10 months after his last pro appearance, working a full season as a starter, just with some extra rest built in. His stuff may never come back to what it was when the Mariners picked him in the second round in 2017, but he throws strikes and changes speeds well, and could surface as a fifth starter, which would be amazing given all the injuries he’s had since he signed. … Starlin Aguilar played in the DSL last year at 17; he’s a stocky infielder who looks like even second base will be a stretch for him, but he has some feel to hit and if he maintains his conditioning he might have utility upside. … Right-hander Bryce Miller, taken in the fourth round in 2021, is 91-96 mph with a short but hard slider. His arm swing is long with effort, and that’s probably why he has well below-average command. … Isaiah Campbell finally made his pro debut in 2021, two years after Seattle drafted him in the second round, but was limited to just 19 innings by a recurrence of the bone spur problem in his elbow that cost him his sophomore season at Arkansas. He has average stuff but throws a ton of strikes with a little deception, possibly a middle guy if he can stay healthy for a full season. … Taylor Dollard throws strikes with an average fastball/slider combo, pitching well in Low A but getting hit hard across the board in High A; there’s no pitch here to give him a chance to be a starter now, but with his control he might have value in relief if his stuff ticks. … Venezuelan lefty Juan Pinto signed with Seattle in 2021 for $700,000; he’s highly projectable with a curveball but has yet to make his debut.
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2022 impact
Rodríguez should make his debut at some point this year, although probably in the second half. Kirby could be up sooner if healthy. Marlowe might be in line for a call-up as an extra outfielder if needed.
The fallen
Joe Rizzo was a questionable pick in the second round in 2016 as a high school infielder who didn’t seem to have a position or any power. He hit .253/.330/.400 last year in Double A, playing around the infield, still without a position. I think it says something about the quality of this system that I couldn’t find an example of a recent Mariners prospect who was either a high pick or a major international signee who’d fared worse in 2021.
Sleeper
I’m all in on Clase’s potential for plus defense in center with power and generally hard contact.
(Photo of Noelvi Marte: Larry Goren / Four Seam Images via Associated Press)
