The Seattle Mariners are coming off one of the best seasons in franchise history. The M’s won 90 games for the third time in five seasons, won their first playoff series win since 2001, and nearly made the World Series before falling in Game 7 of the ALCS versus the Blue Jays. Their MLB core features two of the game’s brightest stars in Julio Rodríguez and defending HR champion Cal Raleigh, an elite closer in Andrés Muñoz, and a starting rotation with three aces all under the age of 30. If that wasn’t enough, Seattle is home to one of the best farm systems in baseball, including seven Top 100 prospects, according to MLB Pipeline. The future looks very bright in the Emerald City!
This article is part of a series focusing on each MLB team’s Top 20 prospects for fantasy baseball heading into the 2026 season. Stay tuned for prospect breakdowns for all 30 teams throughout January here at Pitcher List, and be sure to check out all our published pieces in the series here.
The Top Tier
1) Colt Emerson, SS, Age: 21
2025 Stats (A+/AA/AAA): .285 AVG/.383 OBP/.458 SLG/16 HR/14 SB/17.5% K/11.8% BB
Emerson has become one of the top prospects in all of baseball, reaching Triple-A in his age-19 season. The 22nd overall pick in 2023 had a slow start to his career, as two injuries limited him to just 70 games in his 2024 debut. 2025 was a much different story. He played in 139 games, climbed three levels, and showed why he’s a key part of the Mariners’ future.
Emerson has excellent bat-to-ball skills, as evidenced by a .287 career average in the minors and overall contact rates hovering around 83%. From the left side, he’s shown a propensity to hit the ball with authority to all fields, flashed his natural raw power when needed, and used his athleticism to take the extra base. There isn’t a ton of speed in the profile, but Emerson moves well enough to be impactful on the bases and has enough range and arm strength to stick at shortstop. With incumbent J.P. Crawford manning his natural position, Emerson is likely moving to slide over to either second or third base, possibly as early as Opening Day 2026.
2) Kade Anderson, LHP, Age: 21
2025 Stats (DNP: NCAA)
The Mariners scooped up former LSU Tiger ace Kade Anderson with the third pick this Summer. The 6’1″ left-hander was absolutely electric in his final season with the Tigers, going 12-1 with a 3.18 ERA and an absurd 30.1% K-BB rate. He was particularly dominant in the postseason, throwing 17 innings of one-run ball and leading the Tigers to the national title. After logging 136 combined innings, including the postseason, Anderson did not make his pro debut following the Draft.
From the left side, Anderson has a smooth delivery and easily repeats his mechanics. He’s known to flip change sides of the rubber, creating difficult angles for hitters. Utilizing a high 3/4 release, Anderson has a traditional four-pitch mix, headlined by an excellent four-seam fastball that averages around 93mph with an average of nearly 19 inches of iVB. His slider is his best breaking pitch, flashing above-average spin and getting a ton of Ks. Anderson will also throw a 12-6 curve and a changeup with nice fade. He’s able to attack hitters in the zone and get plenty of whiffs in the process. He has the makeup and arsenal of a potential #1 starter.
3) Lazaro Montes, OF, Age: 21
2025 Stats (A+/AA): .241 AVG/.354 OBP/.504 SLG/32 HR/7 SB/29.0% K/14.2% BB
Montes was the key piece of the 2022 J-15 Class for the Mariners, earning a $2.5M bonus out of his native Cuba. The 6’5″ slugger has quickly developed into one of the premier power hitters in the minors and has posted double-digit homers in all four of his MiLB seasons, including a career-high 32 in 2025. Montes also has a keen eye at the plate, often walking at a very high clip.
Power is clearly the carrying tool in his profile and grades out at 70 in most outlets. Montes uses his big frame and long levers to generate elite bat speed and produce high-end exit velocities, reaching a 90th percentile EV of over 105 mph. He’s able to get to his power early and often, thanks to a 62.1% air rate and a 41.1% pull rate. With big power comes a considerable amount of swing-and-miss, which has manifested itself in strikeout rates creeping up toward 30%. His contact rates have fluctuated throughout his career but generally fall in the 63-68% range. A lack of serviceable defensive ability, mixed with his elite offensive potential, will likely push Montes to a perma-DH role when he reaches the majors.
4) Michael Arroyo, 2B, Age: 21
2025 Stats (A+/AA): .262 AVG/.401 OBP/.433 SLG/17 HR/12 SB/18.7% K/12.4% BB
Arroyo is consistently one of the more underappreciated prospects in baseball. The 21-year-old second baseman from Colombia signed with the Mariners in the same 2022 class as Montes and hasn’t stopped hitting since he debuted that season. At 5’10”, 160lbs, Arroyo lacks the physicality and athleticism of the top prospects in the organization, but his performance gets to elite levels.
Arroyo owns a career .275 average in the minors with an OBP of over .400 and has continuously displayed a well-rounded offensive profile with no discernible weaknesses. From the right side, he is aggressive yet calculated, often flirting with a swing rate of 50% but rarely expanding the zone. Arroyo makes contact at a near-80% rate and has recently started tapping into his raw power without sacrificing his bat-to-ball skills. He’ll never have high-end power, but Arroyo regularly gets the ball into the air to his pull side with ideal launch angles. On the base paths, he uses his instincts and aggressiveness to be impactful, compensating for average straight-line speed. Arroyo has a ’safe’ profile with a relatively high floor, although his ceiling may be lower than most. He’s an ideal second base asset in fantasy who will hit for average, adding some power and speed with consistent counting stats, hitting in the top third of an MLB lineup.
5) Jonny Farmelo, OF, Age: 21
2025 Stats (A+): .230 AVG/.318 OBP/.460 SLG/6 HR/2 SB/29.5% K/10.9% BB
There is a case to be made that Farmelo is the most talented player in the entire system, but a torn ACL early in 2024 has wrecked his young career thus far. Farmelo played just 46 games in 2024 before suffering the injury, but was dynamic before that. He hit .264 with four homers and 18 steals, adding ten doubles and three triples. Recovery from the ACL tear lingered into 2025, where he played in just 15 games before suffering a stress reaction in his ribs, which kept him out until late August. In total, Farmelo has appeared in just 75 games in his first two seasons.
Although we’ve not seen the full scope of Farmelo’s abilities due to limited action, his profile is very fantasy-friendly. Blessed with 70-grade speed and incredible athleticism, Farmelo is a threat to impact the game the second he steps on the field. At the plate, the 21-year-old has drawn walks at a high clip, consistently takes the extra base, and has also flashed a little of his power. A lack of reps has disrupted his timing and elevated his strikeout rate, but generally speaking, his hit tool and power are both above average. Defensively, his speed is a big factor and should allow him to stick in centerfield, which takes a little pressure off his bat early on. If everything clicks and he stays healthy, there’s little doubt that Farmelo has the upside of a Top 25 prospect.
6) Ryan Sloan, RHP, Age: 19
2025 Stats (A/A+): 82 IP/3.73 ERA/27.0% K/4.5% BB
Get used to the name Ryan Sloan, you’re going to hear it a lot very soon. The 19-year-old was the 55th overall pick in the 2024 Draft out of the State of Illinois. Sloan debuted in 2025 and quickly showed why he was given a $3M overslot bonus to forgo his commitment to Wake Forest. At 6’5″, 230lbs, Sloan has the physicality, mound presence, and frame to be a workhorse, not to mention elite stuff.
Everything starts with the fastball for Sloan, which sits 93-95mph and has flirted with triple-digits. He’s able to manipulate its shape and movement to get hitters out in several ways, including by striking them out and inducing weak grounders. His changeup is arguably his most promising pitch, showing excellent fade and easily frustrating hitters on both sides of the plate. Sloan rounds out his arsenal with a slider that has superb depth and has flashed as a third offering, potentially plus or better. The slider can miss bats in the zone and force hitters to chase. The most impressive part of his pro debut was a sub-5% walk rate, a rarity for a first-year pro, let alone a 19-year-old. It’s not out of the range of possibilities that Sloan ends 2026 as the #1 pitching prospect in baseball.
7) Jurrangelo Cijntje, LHP/RHP, Age: 22
2025 Stats (A+/AA): 108.1 IP/3.99 ERA/26.1% K/11.1% BB
By now, you at least know about Jurrangelo Cijntje (pronounced: Sain-juh), the ambidextrous pitcher formerly of Mississippi State and a first-round pick in 2024. Cijntje is definitely a sight to behold, offering the very rare ability to pitch effectively with both hands. In any given inning, Cijntje may throw 10-12 pitches right or left-handed, using his talents to create the most favorable matchups against hitters. While many think it’s just a gimmick, the 22-year-old has major league upside, well, from the right side at least.
I really like the stuff that Cijntje shows as a right-hander. Delivering the ball with a 3/4 arm angle, Cijntje gets to a low release point and offers his four-seam fastball, which averages around 94mph with solid carry up in the zone. He pairs the heater with a mid-80s slider, a curve, and a hard changeup, which doesn’t offer much variation in velocity from the fastball. Cijntje has also worked on a sinker previously, which could be a nice weapon against both lefties and righties if he sticks to his stronger side. As a southpaw, he’s more of a soft-tosser with a low-90s fastball and a big sweeper and projects as a swing reliever. His long-term outlook remains a big unknown, but at some point, you’d expect the Mariners to take a stance and let him focus on being a right-hander, which offers the most upside as a potential #2 or #3 starter.
Prospects Dynasty Managers Should Know
8) Felnin Celesten, SS, Age: 20
2025 Stats (A/A+): .273 AVG/.345 OBP/.375 SLG/6 HR/21 SB/23.5% K/9.7% BB
Celesten got a $4.7M bonus as the prized piece of the 2023 J15 Class, the biggest the organization has ever given out. Injuries kept him off the field in 2023, and then he missed ample time in 2024. The 20-year-old has shown plus speed and is a solid defender, but concerns remain about his hit tool and potential power output. Celesten had a solid 2025, but early results suggest he’s more of a utility player than the star they originally thought.
9) Luke Stevenson, C, Age: 21
2025 Stats (A): .280 AVG/.460 OBP/.400 SLG/1 HR/1 SB/19.0% K/23.0% BB
Stevenson was a highly productive collegiate catcher at North Carolina, mashing 19 homers with 10 doubles and a .414 OBP in his final season with the Tar Heels. He parlayed that performance into a Competitive Balance pick in 2025. The 21-year-old played well in a 22-game sample at Class A, showing outstanding plate discipline and contact skills, along with some power. When you factor in his defensive prowess, the 6’1″ backstop projects as an MLB regular with plenty of offensive upside.
10) Nick Becker, SS, Age: 19
2025 Stats (A): .208 AVG/.321 OBP/.208 SLG/0 HR/2 SB/32.1% K/14.3% BB
Becker is a big, physical shortstop who already stands 6’4″ and around 190 lbs. His athleticism and speed were part of the package that drew the Mariners to him as a 2nd rounder in 2025. His pro debut notwithstanding, Becker profiles as having an advanced hit tool with outstanding pitch recognition but has yet to really find much in-game power despite his size.
11) Korbyn Dickerson, OF, Age: 22
2025 Stats (A): .429 AVG/.556 OBP/.571 SLG/0 HR/0 SB/22.2% K/11.1% BB
Dickerson began his collegiate career at Louisville before transferring to Indiana, breaking out as a draft-eligible sophomore and going as a fifth-rounder in 2025. His breakout with the Hoosiers came from a focus on being more selective, which allowed him to punish mistakes and get to his power more consistently. Dickerson also runs quite well, giving him that highly coveted power-speed blend.
12) Yorger Bautista, OF, Age: 19
2025 Stats (DSL): .223 AVG/.326 OBP/.404 SLG/7 HR/10 SB/29.8% K/9.3% BB
The Mariners added ‘The Beast’ to the fray early in 2025, signing the then-17-year-old Bautista to a $1.7M bonus out of Venezuela. The 6’1″ teenager struggled mightily with contact in his debut, but still showed off the raw power and loud tools that the Mariners expected. Since he just turned 18 in September, Bautista is ticketed for a return to the DSL in 2026.
13) Michael Morales, RHP, Age: 23
2025 Stats (AA): 101.2 IP/4.60 ERA/16.1% K/8.5% BB
Morales has the old-kitchen-sink approach, using five different pitches to get the job done. His strikeouts, which were already deficient, ticked down further in 2025, falling below a 20% K rate. Still, the 23-year-old knows how to pitch and has stabilized his command over the past two seasons. His upside isn’t high, but he still could work as a back-end starter or bulk reliever.
14) Teddy McGraw, RHP, Age: 24
2025 Stats (CPX/High-A): 28.1 IP/3.18 ERA/27.5% K/6.7% BB
Despite having his second Tommy John surgery, McGraw went in the third round in 2023 after his collegiate days at Wake Forest. He’s thrown just 37 pro innings in two seasons after an elbow problem following his debut. If McGraw can get healthy, he’s got three potentially plus offerings, including an electric upper-90s fastball, a nasty slider, and a changeup.
15) Jared Sundstrom, OF, Age: 24
2025 Stats (AA): .219 AVG/.297 OBP/.374/12 HR/35 SB/29.7% K/8.2% BB
The 24-year-old outfielder from UC Santa Barbara has put together consecutive seasons with double-digit homers and 26+ steals. His batting average dipped, and his strikeout rate spiked in 2025. Still, Sundstrom was able to keep his power-speed profile intact even in a very pitcher-friendly environment at Double-A Arkansas.
The Next Five
16) Tai Peete, OF, Age: 20
2025 Stats (A+): .217 AVG/.288 OBP/.404 SLG/19 HR/25 SB/30.6% K/8.7% BB
Tooled-up former first-rounder has yet to find consistency with his bat, but gets a pass because he’s put up above-average production at hitter-friendly High-A.
17) Luis Suisbel, 1B/3B, Age: 22
2025 Stats (A+): .211 AVG/.308 OBP/.412 SLG/23 HR/8 SB/27.5% K/9.8% BB
The 6’1″ corner infielder has seen his contact rates climb each year since his debut while also showing off an outstanding power stroke.
18) Josh Caron, C, Age: 22
2025 Stats (A+): .197 AVG/.269 OBP/.331 SLG/9 HR/11 SB/29.0 K%/7.6% BB
Offensively challenged catcher has struggled to make regular contact as a pro, but is showing some power and has made gains in his receiving and throwing since his debut.
19) Kendry Martinez, SS, Age: 18
2025 Stats (DSL): .157 AVG/.308 OBP/.167 SLG/0 HR/1 SB/27.8% K/15.8% BB
There are no elite tools in his profile, but Martinez projects to have a solid hit tool and some potential power; however, his age-17 season did not flash much of anything.
20) Charlie Beleinson, RHP, Age: 25
2025 Stats (A+/AA): 62.2 IP/4.02 ERA/28.6% K/4.6% BB
Former Duke Blue Devil has found his footing as a reliever, using his fastball, slider, and split change to pound the zone, effectively challenging hitters and inducing a ton of groundballs.
