The Mariners farm system is one of the better systems in baseball. Not only do they have plenty of top talent but they have a deep farm as well. While they have a few MLB-near prospects, most of the farm is high potential younger players. Led by Colt Emerson, the Mariners have drafted mostly high school bats in the last few years. They’ve done well in the international pool as well with Felnin Celesten, Lazaro Montes, and Michael Arroyo. If the Mariners’ prospects can improve in 2025 as much as they did in 2024, they might end up with eight top 50 prospects in baseball.
Head over to the Pitcher List dynasty page to check out the other prospect rankings already published.
- NL East: Phillies, Mets, Marlins, Nationals
- NL Central: Reds, Cardinals, Brewers, Pirates, Cubs
- NL West: Diamondbacks, Dodgers, Giants
- AL East: Red Sox, Yankees, Orioles, Rays, Blue Jays
- AL Central: Tigers, Guardians, Twins, White Sox, Royals
- AL West: Astros, Athletics, Rangers
Top Mariners Prospects
The Top Tier
1) Colt Emerson – SS, 19 YO
2024 MiLB Stats (ROK/A/A+): .263/.393/.376/4 HR/15 SB/ 17.3K%/ 14.9BB%
Arguably the top overall prospect in baseball, Emerson may have forced that narrative if healthy. Emerson has had a great start to his professional career but has been limited due to injury. With a near 1:1 strikeout to walk rate in 2024, Emerson showed a great approach. Projectability became higher entering 2024 as Emerson added some clear size to his frame. While the power has yet to translate to home runs, Emerson has all the tools.
Reaching High-A in his age 19 season, Emerson didn’t struggle until those 29 games. The hit tool dipped, but most of the rest of his game stayed the same. He’ll be 19 until late July, and the Mariners should start him in High-A. When Emerson learns to tap into his power, he should see 25/20 seasons. The hit tool and approach will lead to plus average and OBP numbers, making Emerson a five-category threat. Most of the prospect world is high on Emerson and just needs to see a healthy 2025 season.
2) Cole Young – SS, 21 YO
2024 MiLB Stats (AA): .271 / .369 / .390 / 9 HR / 23 SB / 15.8 K% / 12.1 BB%
Drafted out of high school in the 2022 MLB Draft, Young has impressed. The 21st overall pick can hit. Young has a .279 career MiLB average, paired with a strikeout rate never above 16.5%. Young and Harry Ford are the two most likely to debut for Seattle soon into 2025. More of an old-school second baseman, Young is hit first with good speed. Young has average power and should be able to tap into 15 per season.
A top-of-the-lineup hitter, Young should work his way up to become the Mariners’ lead-off hitter by 2026. A true contact approach, Young has been advanced at the plate since he was drafted. Young doesn’t strike out at a high rate and manages a good walk rate. The next step is advanced pitching for the 21-year-old. While it would be aggressive, the Mariners could give him a shot out of spring training. A team that has needed offensive help, Young could be that spark if the Mariners’ offense is off to a slow start in 2025.
3) Jonny Farmelo – OF, 20 YO
2024 MiLB Stats (A): .264 / .398 / .421 / 4 HR / 18 SB / 23.5 K% / 16.3 BB%
Farmelo was my favorite upside pick out of the 2023 MLB Draft. He looked the part in his short 2024 debut, and his tools were on display. Unfortunately, Farmelo tore his ACL and won’t be back until August 2025. When on the field, Farmelo uses a compact, but quick and powerful swing. The raw power and plus speed make Farmelo an easy 20/20 candidate.
A lot of improvements still need to be made, but Farmelo has power and speed in his game. The strikeout rate is the biggest concern, as he had 52 Ks in 178 ABs. Farmelo showed a good approach as he managed a 16.3% walk rate. The swing decisions weren’t the issue, but the swing and miss is in his profile. His speed is his calling card, and with a good walk rate, he could snag north of 30 stolen bases per season. The raw power should allow him to tap into 20 home runs without issue. The hit tool and swing and miss are going to control what moves Farmelo. Look for 2025 to be a slow-moving season recovering from a torn ACL.
4) Lazaro Montes – OF, 20 YO
2024 MiLB Stats (A/A+): .288 / .397 / .484 / 21 HR / 5 SB / 23.6 K% / 14.4 BB%
An imposing presence, Montes stands 6’3″ and 210 pounds as a 20-year-old. One of the top prospects in baseball, Montes has drawn similarities to Yordan Alvarez. While that is nearly impossible to replicate, Montes is trying his best. Consistently putting up solid numbers, Montes broke out with 21 HR in 2024. The strikeout rate is something to monitor but he kept it to 23.6% overall in 2024.
The upside for Montes comes with risk, but there is an argument he’s the clear No. 2 prospect in the Mariners system. In 51 High-A games, Montes saw his strikeout rate jump to nearly 30%. The positive is that he was just 19 years old, and hit eight home runs in those 51 games. The offensive profile is always going to be power first, but Montes is showing a good ability to hit for average. It’s easy to dream on the upside here, and Montes could become a top-10 prospect in baseball very quickly in 2025.
5) Harry Ford – C/OF, 21 YO
2024 MiLB Stats (AA): .249 / .377 / .367 / 7 HR / 35 SB / 22 K% / 14.1 BB%
A top prospect in baseball for what seems like a while, Harry Ford was taken 12th overall in 2021. Immediately successful, Ford has displayed a plus approach and plate discipline. He’s never seen more than one level per season but has been promoted each offseason. Ford might see a more aggressive promotion style in 2025 as the Mariners need bats. Having an outside shot of winning a spot out of spring training, Ford could see a split between catching and outfield.
Speed and plate discipline, along with his defensive ability, are going to carry Ford. A 20+ steal threat each season, Ford sees more opportunities to steal due to a great walk rate. The hit tool has taken a dip in the last two seasons, but Ford has a quick compact swing. The upside here is 20/20 potential from the catcher spot, which makes him a top option at the position. Ford has a chance to make an impact in 2025 near the middle of the season.
6) Michael Arroyo – SS/2B, 20 YO
2024 MiLB Stats (A/A+): .285 / .400 / .509 / 23 HR / 18 SB / 23 K% / 12.3 BB%
A Mariners prospect that seemingly gets lost in the shuffle is Michael Arroyo. The numbers have been solid since he was signed in 2022, but 2024 was a mini breakout. Arroyo was able to show off a bit of each tool in 2024, flirting with multi-tool potential. Arroyo will be 20 years old for the entire 2025 season, and he could catapult himself into the top 50 prospects in baseball.
Splitting his games evenly in 2024, Arroyo spent 60 games at Low-A and High-A. The small, 5’8″ prospect showed off the raw power, hitting 23 home runs in 2024. Adding 18 steals, a .400 OBP, and a .285 average, Arroyo dominated. The split from Low-A to High-A was even in nearly every category, as the stats mirrored each other. The size is the only concern at the moment here, as it may be tough to consistently see north of 20 HR per season. Even with a 15 HR season, Arroyo has plus bat-to-ball skills, and good speed to make him a four to five category threat. Arroyo is a clear top 100 prospect and is knocking on the door of the top 50.
7) Jurrangelo Cijntje – RHP/LHP, 21 YO
2024 MiLB Stats: N/A
The most recent top draft pick for Seattle is the electric dual-arm-throwing Jurrangelo Cijntje. Pitching with both his right and left hands, Cijntje is Must See TV. More dominant with his RHP ability, the dual threat gives him another advantage. He struggled as a 20-year-old in the SEC, but his second season was a different story. Cijntje went from 50 innings to 90.2 innings and walked four fewer batters with nearly a five-run improvement to the ERA. This landed him in first-round conversations where the Mariners picked him at 15th in 2024.
A mid-90s fastball from the right side, Cijntje pairs that with a hard slider and changeup. The velocity is there from the right side, and he has the potential to be a No. 2 or No. 3 starter in the majors. It remains to be seen how he’ll be used as a left-handed pitcher, but the stuff isn’t quite as polished from the left side. Cijntje is a good athlete and repeats his delivery well. The clear split advantage from using one pitcher is an interesting one, and something the Mariners will play with to start his career.
Prospects Dynasty Managers Should Know
8) Felnin Celesten – SS, 19 YO
2024 MiLB Stats (ROK/AA): .352 / .431 / .568 / 3 HR / 5 SB / 19.4 K% / 12.5 BB%
The Mariners’ top international singing in 2023, Felnin skipped the DSL and didn’t debut until 2024. The tools are there for Felnin as he crushed the ACL in 2024. A .352 average showed why the Mariners spent $4.7M on Celesten. He has a chance to be the Mariners No. 1 prospect midway through 2025. The upside here could land him a few spots higher, but his track record is important. With just 32 games in 2024, Celesten most likely would have seen some late-season Low-A action. Look for both Low-A and High-A action from Celesten in 2025.
9) Ryan Sloan – RHP, 18 YO
2024 MiLB Stats: N/A
Drafted 55th overall in the 2024 MLB Draft, Sloan was mocked as a first-round talent. The Mariners were able to snag him in the second round, and the pure talent is a steal there. Sloan has above-average stuff across the board and will be 19 years old for all of 2025. Sloan has a fastball that lives in the mid-90s and possesses a slider and changeup that could be plus offerings. Both are good right now, but we’ll see which one plays as the better secondary in 2025. With high strikeout potential, Sloan will most likely see most of 2025 at Low-A.
10) Tai Peete – SS, 19 YO
2024 MiLB Stats (A): .269 / .343 / .408 / 7 HR / 45 SB / 30.7 K% / 10.2 BB%
Drafted 30th overall in 2023, Peete won’t turn 20 years old until August 2025. The hit tool is currently lacking and it is leading to a high strikeout rate. Outside of the hit tool, Peete possesses plenty of talent. Plus speed and above-average raw power, Peete could be a 20/20 player in the majors. However, 162 strikeouts in just 115 games is a major concern. With youth on his side, Peete has time to work on improving his bat-to-ball skills. The upside here gives Peete the 10th spot on the Mariners prospect list.
11) Logan Evans – RHP, 23 YO
2024 MiLB Stats (AA): 107 IP / 3.20 ERA / 21.9 K% / 9.4 BB%
A 12th-round pick in 2023, Evans has dominated in his pro debut. With a career 2.88 ERA in MiLB, Evans reached Double-A in 2024. Throwing only 107 innings in 2024, Evans limited the hits but walked a high amount of batters. Projecting as a back-end starter, Evans has good, not elite stuff, and he will need to lower that 9.4% walk rate. As he continues to see better hitters, this will be the biggest hurdle. A top spot start candidate, Evans will need an injury to crack that star-studded Mariners rotation. A move to the bullpen or a trade may be the quickest route to the majors for Evans.
12) Cole Phillips – RHP, 21 YO
2024 MiLB Stats: N/A
Drafted in 2022 by the Atlanta Braves, Phillips has yet to pitch a professional inning. With two Tommy John surgeries in two seasons, Phillips has been very unlucky. The risk is high here, but the pure stuff Phillips showcased prior to the 2022 MLB Draft makes him intriguing. Drafted behind Owen Murphy in 2022, Phillips has an electric fastball. Hoping to debut in 2025, Phillips will most likely be moved slowly with an extreme innings limit.
13) Michael Morales – RHP, 22 YO
2024 MiLB Stats (A+/AA): 149 IP / 3.02 ERA / 24.1 K% / 6.2 BB%
A third-round pick out of high school in 2021, Morales struggled in his first three pro seasons. Unable to command his pitches and limit contact, Morales didn’t find success. 2024 was a complete flip of the switch for Morales. The walk rate dropped roughly three percent, and he limited the hits allowed. Morales pitched to a 3.02 ERA in 2024, a full 1.50 ERA lower than his previous season. The stuff is still average across the board, but Morales could be a fourth or fifth starter if he can continue his 2024 success.
14) Teddy McGraw – RHP, 23 YO
2024 MiLB Stats (A): 8.2 IP / 4.15 ERA / 20 K% / 10 BB%
A third-round pick in 2023, McGraw has yet to pitch a good amount of innings due to Tommy John surgery. With just 8.2 MiLB innings under his belt, McGraw has flashed the stuff. A true three-pitch mix pitcher, McGraw has three above-average offerings. The upside is there, but the track record is not. All three of his pitches project to be strike-out pitches, but his changeup has the greatest downward movement of the three. His fastball/changeup combination was mostly on display in his short 2024 season. Look for the Mariners to open it up for McGraw in 2025.
15) Brandyn Garcia – LHP, 24 YO
2024 MiLB Stats (A+/AA): 116 IP / 2.25 ERA / 27 K% / 9.5 BB%
An older pitching prospect, Garcia was an 11th-round pick in 2023. While he’s had tremendous MiLB numbers since being drafted, Garcia has yet to play above Double-A. Projected as a back-end starter, Garcia will be tested against better talent in 2025. Garcia did a good job of limiting contact, but the walk rate is a bit high. With 134 strikeouts in 116 innings last season, Garcia managed to get swing and misses. His fastball is his best pitch, but the biggest hurdle is control as he continues to see promotions. With a real shot to debut in 2025, Garcia could see that opportunity coming out of the Mariners’ bullpen.
The Next Five
Although these prospects do not crack the top 15, dynasty managers should keep their eye on these five players:
Dawel Joseph – 17 YO – The Mariners’ top 2024 international signing, Joseph had a very disappointing DSL debut.
Jeter Martinez – 18 YO – A top international signing in 2o23, Martinez has great stuff with command being a major obstacle.
Ben Williamson – 24 YO – A second-round pick in 2023, Williamson makes good contact but doesn’t provide much else.
Brock Rodden – 24 YO – Contact bat & utility player with 15 HR/20 SB potential.
Josh Caron – 21 YO – A fourth-round pick in 2024, Caron hit .308 with 16 HRs in his final collegiate season.