Logan Gilbert, Taylor Trammell, and Jarred Kelenic have graduated from the top 10 this year but loads of talent remains in one of the deeper systems in baseball.

Clicking on the team (level) will take you to the full, official, current roster.


DSL Mariners (R)

George Feliz, CF
Feliz has lived up to his ends of the bargain early in his debut in the Mariners organization. He batted .381/.469/.738 with eight extra-base hits and five stolen bases in 11 games. He’s been compared to Nationals outfielder Victor Robles, but I’ve also heard Andres Torres and Shane Victorino.

Gabriel Gonzalez, OF
He may up in a corner, putting pressure on the bat and especially the power, but hit .347/.433/.571 in 14 games in July, including three doubles and three home runs. He’s just 5-foot-11 and 175 pounds, but the bat speed and bat-to-ball skills are showing out in the DSL.

Edryn Rodriguez, 2B
He’s not talked about much but has good bat speed and a mature swing path. He’s probably limited to the middle of the field offensively, but has the athleticism to stay at second base or slide into center.

Starlin Aguilar, 3B
Aguilar may not stick at the hot corner but has the arm for it and ranks ahead of Milkar Perez on the ‘chances to stick’ depth chart. Aguilar projects to hit for some power, but how far and how fast he moves up the ladder will depend on how quickly he turns his raw tools into skills. He’s making consistent contact, a great sign the power come in time.

Adrian Quintana, RHP
Quintana is among the more projectable arms on the roster at 6-foot-1 and 180 pounds at age 18. His arm is quick, and he’s touched 90 mph with projectable slider and changeup. He’s punched out nine in 11 innings for work for the DSL Mariners, two of those scoreless outing. He went five shutout innings last time out, including five strikeouts and no walks.


Arizona Mariners (R)

Milkar Perez, 3B
Perez, 19 until October, hit .284/.478/.343 in July, an odd slash, but one that’s common in rookie ball as inexperienced hitters with advanced plate skills show mixed results.

Luis Chevalier, 2B
He’s likely limited to second base, but Chevalier has flashed some hitting ability early in the ACL, despite his .219 batting average. He’s drawn 15 walks and collected five extra-base hits in July. He won’t turn 20 until January.

Jonatan Clase, CF
In 14 games he posted mixed results with a .245/.333/.388 slash, but went 16-for-16 in the stolen base department. He hasn’t played since July 19 due to an undisclosed injury, but won’t be 20 until next May and his 70 speed and raw athleticism are an exciting package of clay for the Mariners dev staff.

Michael Limoncelli, RHP

The 6th-round pick from the 2019 draft class is back on the mound after sitting out most of ’19 and all of 2020 rehabbing from Tommy John surgery. While he’s struggled to throw consistent strikes, the stuff is most or all of the way back, as evidenced by his 20 strikeouts in 16 innings in July. At his best he’s 90-92 mph with a solid-average curveball. The club hopes they can safely max out his velocity, develop the changeup and take advantage of his athleticism.

Yeury Tatiz, RHP
The 20-year-oldtTatiz brings projection with his 6-foot-3, 185-pound frame and a fastball into the low 90s. He’s missing bats in the ACL (19 in 14.2 IP), but catching a lot of the plate and struggling with control.

Luis Baez, RHP
There was a time just three years ago Baez was my No. 25 prospect. The fact he’s now unranked has more to do with the club’s farm vastly improving than his struggles, but the right-hander has had problems throwing strikes with consistency. But he’s a good arm with velocity projection, missing bats at every step so far.


Modesto Nuts (Low-A)

Noelvi Marte, SS
Marte struggled over an extended period for the first time in his professional career, batting .219/.270/.316 in July. He continues to show maturity, however, both on and off the field, and defensively the belief he stays on the dirt grows as the season progresses.

The Manny Machado comps makes some sense, though the Padres third baseman broke into the big leagues with the Orioles three and a half weeks after he turned 20.

The power does stand out for Marte, but the most impressive part of his 2021 season to date may be his increasing consistency with everything from his glove work to throwing to the bounce back he’s now experiencing after a tough month.

Adam Macko, LHP
Macko sat out for nearly six weeks with soreness and has battled bouts of control problems in his eight starts but the stuff and athleticism cannot be denied. He’s punched out 36% of the batters he’s faced, flashing 92-95 mph velocity, an above-average slider and average changeup.

Macko needs work-up time to build arm endurance and improve his control, but once the switch flips he may move quickly.

Connor Phillips, RHP
Phillips is built like a big-league arm and flashes three major-league pitches, including velocity into the mid-90s. He, too, has struggled with control but walked just two batters in his final two starts in July. Overall, the stuff still can be a bit hittable at times, but he’s just 20 years old and 49 innings into his pro career, and there have been signs of dominance.

Phillips has a shot to develop into a mid-rotation starter, but it’s likely to take some time to work on the mechanics and develop the secondaries.

Sam Carlson, RHP
Carlson started the year with fire, then struggled with command in June and July,and saw his velocity dip down after his first few outings into the 88-91 mph range.

It’s ticked up a bit of late and he finished July strong, posting a 15-5 K/BB ratio over his final three outings of the month. His slider is his best pitch and the fastball does get ride up and to his arm side.

While he’s 22 and older than a lot of the hitters he’s facing, this season has always been about rebuilding his arm strength after missing nearly four years with arm problems. He’s a great athlete — maybe the best in the entire organization — and despite the fluctuation in velocity he’s piled up 78 strikeouts in 67.2 innings of work. I still see a No. 3 starter here, but he’s not likely to move swiftly through the lower minors and as a result will be a tad older than the media age until he hits Triple-A.

Alberto Rodriguez, OF
After a bad May — .173/.281/.293 — the 20-year-old Rodriguez hit .298/.395/.497 over the next two months. He was the return in the trade with the Toronto Blue Jays for Taijuan Walker and has a chance to develop into something at the plate.


Everett AquaSox (High-A)

George Kirby, RHP
Kirby started the season looking rather ordinary for a prospect of his status, but since mid-June or so has turned it up a notch. In July he made just two starts after sitting out to curb fatigue and soreness but picked up right where June left off. He’s been up to 98 mph with above-average command, and a slider that’s quickly developing into his best secondary offering.

Kirby, slated to go Saturday in Spokane, could see Double-A Arkansas once he’s ramped back up after nearly a month off. His last start — July 10 in Eugene — was his best as a pro: 7 IP, 4 H, ER, BB, 11 SO. Once the Mariners take the kid gloves off, the right-hander is likely to scream through the minors.

Emerson Hancock, RHP
Hancock just returned from time on the shelf with soreness, too, but it’s important to note the Mariners have asked their arms to be aggressively upfront about fatigue and any soreness beyond the expected.

Last year’s No. 6 overall pick has flashed a plus slider and a fastball 93-96 and touching 98. He’s also shown a solid-average changeup and the arm speed and finish the Mariners loved about him last spring.

Hancock may not move as quickly as Kirby as he works through potential fastball concerns — it’s not a swing-and-miss pitch and its movement is mostly down in slightly sinking fashion. Hancock is learning to use it up in the zone.

He made just one start in July, but barring additional setbacks is expected to be in the rotation in Everett most of, if not the entire rest of the season.

Taylor Dollard, RHP
Dollard doesn’t have the advanced stuff of Kirby and Hancock, and in starts where he’s struggled to avoid the middle of the zone he’s been hit pretty hard. He’s still missing bats and throwing strike — 33 strikeouts, 7 walks in 35.1 innings — but the seven homers he’s allowed isa bit of a concern, and perhaps further evidence his future lies in a relief role.

Juan Then, RHP
Then has had an uneven 2021, which was not unexpected, at least for me. He’s a little shy on stuff for a starter as he develops his changeup, and he’s battled some control issues at times, forcing him to pitch a lot with runners on base.

Then made just one appearance in July.

When healthy he’s 92-96 mph with a 55 slider that flashes plus, and in a bullpen role Then might turn into Edwin Diaz 2.0. But he’s still just 21 and likely stays in the rotation plans for at least another year. Which is exactly what Diaz did at the same stage.

Victor Labrada, CF
Labrada’s upside is limited but he can run and defend, and if he can find a way to cut down on the strikes has a chance to be a good fourth outfielder.

He batted .333.412/.467 in July, earning a promotion to Everett in the process.


Arkansas Travelers (Double-A)

Matt Brash, RHP
Brash has relentlessly pounded the strike zone with plus velocity into the upper-90s, sitting 94-98, and complementing with two breaking balls, including a plus power slider with late break and tilt.

He’s the furthest along of the starting pitching prospects not named George Kirby and may beat the former first-round pick to the major leagues.

There’s a changeup at the bottom of his arsenal but it’s firmly below average at present.

He’s simply extended his 2021 success from High-A Everett to Double-A Arkansas, and from June into July.

Brandon Williamson, LHP
Williamson’s July was uneven. He allowed 16 earned runs on five longballs in five starts. He struck out 28 in 24.2 innings, but yielded 33 hits.

The lefty isn’t overpowering but has touched 97 mph in shorter stints with his fastball. This season he’s been mostly 91-94 mph, touching 95, creating deception with his front side, and coming back with an above-average curveball. His slider and changeup are works in progress, but the slider has sweeping action and has helped him versus left-handed batters.

Levi Stoudt, RHP
Stoudt spent all of July in High-A and had three solid starts and one bad one that ballooned the numbers for the month. Mostly 92-96 mph for Stoudt on his fastball, but he’s been up to 98.

The right-hander’s control hasn’t been consistent, and his slider is fringy. His plus changeup hasn’t been consistent, either, and all three of his pitches have come and gone. Having said that, there are times when his command is average or slightly better, and his slider and changeup fall in line. They just don’t happen enough all at once, or even two of the three.

There was word he’d scrapped his curveball but he’s brought it out at times, perhaps to give him another option when the feel isn’t there on his other pitches.

Ray Kerr, LHP
Kerr has a big fastball into the upper-90s and has touched triple digits, setting up an average to above-average slider that has gained consistency over the course of the season. When he locates, he’s devastating.

Kerr has started in the past, and his athleticism offers a chance at repeatable mechanics that lead to more consistent command, which is the biggest obstacle in front of him and the majors.

Kerr posted a 15-1 K/BB ratio over nine innings in July.

Patrick Frick, SS
Frick is a fringe prospect but has the physical tools of a Whit Merrifield and is having a strong season at the plate. In July, Frick batted .318/.431/.476, including two multi-games in four contests to start out his Double-A career.

He’s 24, but so was Merrifield when he hit AA for the first time, and he’d squeak into the big leagues at 27 and have a nice career –one that’s still going.

No reason Frick can’t do the same.

And yes, you can call this a comp.

Zach DeLoach, OF
DeLoach torched the High-A West after a slow month of May, batting .363/.442/.549 in June and .349/.438/.635 in July and earning a trip to Double-A as a result.

He’s one of those “nothing jumps off the page” prospects, unless you watch him regularly and see how consistent he is with everything from swing quality to pitch selection.

The game power is more doubles than home runs right now, but I believe that changes similarly to the way Austin Shenton‘s began to in 2021, and July may have been the first sign of that for DeLoach. He hit for average and hit four homers in 14 games, by far the best of his young pro career in that department.

Kaden Polcovich, 2B
The club’s third-round pick in 2020 isn’t a traditional scouting job. He’s merely 5-10 and 185 pounds listed, but the swing packs a punch and he’s been willing to give a bit on contact in order to get to the power.

Typically that might suggest a problem with the game plan, and while the club may prefer he makes more contact down the line, he’s throwing .400+ OBPs all year and if he can sustain higher on-base marks, I don’t care one bit if he strikes out more than his physical profile suggests he should.

Polcovich hit .306/.471/.612 in July, however, doing it all in 15 games before getting own promotion papers to Arkansas. He runs well, though isn’t a burner.

I’ve seen him play an average shortstop and center field, and above-average defense at second, and with more consistency at second and out in center, could play either spot regularly.

Julio Rodriguez, OF
Rodriguez has been off helping the Dominican Republic compete in the Olympics and played just 12 games in the minors in July, but performed well in those 12 — .293/.431/.537 to be exact.

He also played just seven games in June, so the fact he’s managed just 40 games and fewer than 200 plate appearances this season isn’t good for his development, but the Mariners couldn’t tell him he couldn’t compete in the Olympics.

Sure, he received a bit of experience in the trials and Tokyo Games, but the sample is microscopic versus what he would have received.

When he’s played, Julio has been Julio, showing an improving hit tool and easy 65-grade power. There are some mechanical questions about his swing, but some have bene addressed prior to the start of the ’21 season, and we’ll see if the others need to be fixed as he sees better pitching moving forward.


Tacoma Rainiers (Triple-A)

Taylor Trammell, OF
Technically, Trammell is not a prospect, but to be honest I don’t believe MLB should be allowed to dictate what a prospect is by their arbitrary inning and at-bat totals, so starting this coming winter I will be changing my guidelines for prospects to less than a year of big-league service and fewer than 500 plate appearances for hitters, no more than 50 innings pitched for relievers, and no more than 150 innings pitched for starting pitchers. For pitchers who appear widely as both starters and relievers, the 150-inning limit will apply.

Trammell has quick-twitch actions with his hands that stand out when watching him hit, and his power has jolted from 45 to 60 raw inside of two years as he’s made swing adjustments.

I do wonder, however, if he creates some bat drag during his load.

Drag happens when the barrel strays away from the body. It can happen at the start of a swing when the batter extends their elbow, or when the hands sink aggressively down and/or away from the body or barrel. Younger hitters, youth, high school, even college-level, experience the most common version of drag by creating a very long path for the barrel to get to the zone. This happens when the back elbow thrusts ahead toward the pitcher, leaving the hands — and most importantly, the barrel of the bat — a greater-than-ideal distance from the zone. Not only is the barrel too far away, this is a position that limits raw bat speed, too.

Trammell may be guilty of one of the former two versions sometimes (I don’t have adequate video), though if that is the case, the staff in Tacoma knows, and if they see it as a problem they’ll help him fix it. Drag is never good, though there are varying degrees of it and it occasionally can be overcome.

In 14 games in July, Trammell went 8-for-39 in Tacoma, but the strikeout rates were not high, and he finished the month 7 for 19 with two doubles and a homer.

He plays a strong center field despite 45-grade arm strength and is one of the better baserunners in the organization. I think it’s simply a matter of time before Trammell hits.

Penn Murfee, RHP
Murfee spent half of July in Double-A Arkansas and half in Tacoma. He hiccupped July 22, but has otherwise been solid for the Rainiers.

It’s ordinary stuff, really, including a low-90s fastball and 50-55 grade slider, but he creates deception and funky angles by dropping down around sidearm.

I see him as a middle reliever with some Chris Devenski upside; in shorter stints perhaps 89-92 turns into 93-96. There’s some Paul Sewald in him stylistically.

Ian McKinney, LHP
McKinney is fun to watch. He’s athletic, works fast, and generally commands an 89-92 mph fastball up to 94, and a plus curveball. He’s improved his sweeping slider and a changeup to help him versus righties and it’s paying off big time.

He, too, creates some deception with shoulder angles and by staying closed a long time, and McKinney locates, he’s very tough to hit. He gets into trouble when he nibbles — 13 walks in 22.1 innings in July — and he’s a fly ball arm pitching in mostly hitter-friendly ballparks in the PCL right now.

He’s probably a reliever at the next level but could be useful as early as September, especially considering Justin Dunn isn’t close to throwing yet with six and a half weeks left in the season.

Got a take on what you just read? Talk about it here!

Image courtesy of Seattle Mariners
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Jason A. Churchill

Churchill founded Prospect Insider in 2006 and spent several years covering prep, college and pro sports for various newspapers, including The News Tribune and Seattle PI. Jason spent 4 1/2 years at ESPN and two years at CBS Radio. He now serves as the Executive Copy Editor at Data Skrive, a tech company that manipulates data to provide automated content to clients including the AP, BetMGM, USA Today, and ESPN. Find Jason's baseball podcast, Baseball Things, right here.

1 Comment

  1. Great post! From reading it, sounds like Matt Brash has taken the biggest leap up of any of the prospects. Is this correct? Anyone else who has opened some eyes or taken a big step up so far this season? Maybe Trammell with his power increase.

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