2026 Mariners Top 20 Fantasy Baseball Prospect Rankings

The Mariners seem to have no problem turning top pitching prospects into elite Major League Pitchers. Are there some bats on the way that might help push the team to the next level? In this article, we’ll profile the top 20 fantasy baseball prospects of the Seattle Mariners

About our rankings

These prospect rankings are strictly fantasy-focused. While they are performance-informed, our rankings also lean heavily on upside. A high-OBP slugger with game power and pedigree is going to rank higher than a speedy slap hitter with limited fantasy impact, even if the latter is closer to the majors. Likewise, you can usually grab a league-average pitcher from the waiver wire. Our rankings will value the pitchers with the upside to be No. 1 and 2 starters much more highly than command pitchers who look to be roster filler.

Seattle Mariners Top 20 Fantasy Baseball Prospects

These Top 20 Seattle Mariners Fantasy Baseball Prospect Rankings are largely based on our Top 500 Dynasty Rankings, along with our Top 600 Fantasy Baseball Prospects, with a little tweaking done to accommodate recent news. Updates for both of those lists are also in the works and will be coming in short order.

Colt Emerson (SS) – MLB ETA: 2026

Age: 20 | Current Level: AAA | Bats: L | Throws: R

Emerson made his MLB debut in mid-May 2026 after a $95M extension and is widely viewed as the Mariners’ top hitting prospect, with a smooth, instinctual approach at shortstop and a hit tool that grades plus across the board. He’s an everyday shortstop with a clear path to a long-term infield role, and scouts rate him the best defensive infielder and best infield arm in the system. Dealt with a back issue mid-June but is expected back quickly. A must-own across dynasty formats regardless of format.

Kade Anderson (LHP) – MLB ETA: 2026

Age: 21 | Current Level: AA | Bats: L | Throws: L

The No. 3 overall pick in 2025, Anderson opened 2026 in Double-A Arkansas and has been arguably the most dominant pitcher in the minors, sitting atop Double-A in nearly every pitching category and tying for the MiLB strikeout lead in June. He pairs a fastball that grades plus with a changeup and feel for both sides of the plate, and is regarded as having a clean, fast-moving path to a mid-rotation MLB role. Some compare his deception and polish to Max Fried.

Ryan Sloan (RHP) – MLB ETA: 2026/2027

Age: 20 | Current Level: AA | Bats: R | Throws: R

A 6’5″, 220-pound power arm who debuted with the Mariners in 2024 out of an Illinois high school, Sloan opened 2026 in Double-A and has trended toward front-line starter upside despite a bumpy ERA in his first several outings. He’s bounced back strongly of late, including a perfect six-inning, 11-strikeout start in late May. Some evaluators have him rated above Anderson long-term, given his size, stuff, and age relative to level.

Michael Arroyo (2B) – MLB ETA: 2026/2027

Age: 21 | Current Level: AA | Bats: S | Throws: R

Arroyo opened 2026 in Double-A Arkansas after an active spring that included time with Team Colombia in the WBC. He’s regarded as having the best strike-zone discipline in the system, a switch-hitting profile with feel to hit from both sides, and projects as a future everyday second baseman. He impressed evaluators in big league camp this spring alongside fellow top prospect Ryan Sloan.

Lazaro Montes (OF) – MLB ETA: 2026/2027

Age: 21 | Current Level: AA | Bats: L | Throws: R

Montes is the system’s premier boom-or-bust power bat, having flashed exit velocities north of 116 mph and a raw power grade among the best in the minors. He’s already hit 20-plus home runs again in 2026 at Double-A Arkansas, continuing a three-year streak. The swing-and-miss is real — his contact rates remain below average — but the upside is a middle-of-the-order force if the hit tool catches up to the power.

Jonny Farmelo (OF) – MLB ETA: 2027/2028

Age: 21 | Current Level: A+ | Bats: L | Throws: R

Farmelo’s career has been defined by injury — a torn ACL in 2024 and a rib stress fracture in 2025 limited him to roughly 350 total pro plate appearances — but the tools remain loud. He carries a 70-grade speed grade and has rebounded with a strong June at High-A Everett, slashing well over .260 with 18 steals. If he can stay on the field, he profiles as a dynamic, high-ceiling center fielder.

Felnin Celesten (SS) – MLB ETA: 2028

Age: 19 | Current Level: A+ | Bats: S | Throws: R

Celesten received the largest international signing bonus in franchise history ($4.7M) in 2023 but has been slowed by multiple injuries since. He’s enjoying a strong rebound in 2026 at High-A Everett, posting an OPS near .900 through mid-June with his first career grand slam, and remains a switch-hitting shortstop with plus defensive tools. Still just 19, he has real helium if the bat-to-ball skills hold.

Yorger Bautista (OF) – MLB ETA: 2030

Age: 18 | Current Level: ROK | Bats: R | Throws: R

Nicknamed “La Bestia” (The Beast), Bautista signed for $1.7M out of Venezuela and showed loud raw power and bat speed in his pro debut, but struggled badly with contact, striking out nearly 30% of the time. He remains a long-term, high-variance ceiling play whose path to relevance hinges entirely on tightening up his approach against more advanced pitching.

Teddy McGraw (RHP) – MLB ETA: 2027

Age: 24 | Current Level: A+ | Bats: R | Throws: R

A two-time Tommy John surgery survivor nicknamed “Curveball Jesus” for a pitch that’s already considered close to MLB-ready, McGraw has dealt with a fresh elbow issue in 2026 that has limited his innings. When healthy, his curveball and heavy sinker give him swing-and-miss and ground-ball upside that could play in the big leagues quickly — the swing skill has never been the question, durability has.

Carlos Jimenez (OF) – MLB ETA: 2028

Age: 23 | Current Level: A+ | Bats: R | Throws: R

Jimenez opened the 2026 season with Everett in High-A as a depth outfield piece in a crowded Mariners system. He doesn’t carry the prospect pedigree of the names above him, but provides organizational depth with a decent all-around tool set, profiling more as a potential up-and-down contributor than an impact regular.

Luke Stevenson (C) – MLB ETA: 2028

Age: 21 | Current Level: A+ | Bats: R | Throws: R

A Competitive Balance pick out of North Carolina in 2025, Stevenson mashed 19 homers with a .414 OBP in his final college season and translated that into an excellent pro debut, flashing power, patience, and contact skill in a 22-game Single-A sample. He also benefits from mentorship under Cal Raleigh, and projects as a potential everyday catcher with real offensive upside thanks to his defensive polish.

Nick Becker (SS) – MLB ETA: 2029

Age: 19 | Current Level: ROK | Bats: R | Throws: R

A cold-weather prep prospect out of New Jersey who signed for an over-slot $2.75M as the Mariners’ 2025 second-rounder, Becker is a plus runner and good athlete who projects to stick at shortstop with above-average power down the line. The hit tool is the swing skill that needs the most projection, and he’s currently working through extended spring training.

Griffin Hugus (RHP) – MLB ETA: 2029

Age: 22 | Current Level: ROK | Bats: R | Throws: R

Hugus, a 2025 third-round pick out of Miami, impressed in his brief pro look before injuring his elbow in spring training and undergoing Tommy John surgery, wiping out his 2026 season. Pre-injury, scouts liked his low release height, deception, and projectable slider, giving him a real shot to start long-term once he returns.

Korbyn Dickerson (OF) – MLB ETA: 2028

Age: 22 | Current Level: A | Bats: R | Throws: R

A third-round pick out of Indiana in 2025 after transferring from Louisville, Dickerson has been one of the hotter bats in the system this year at Single-A Inland Empire, slashing .300/.405/.567 in a recent month-long stretch. He’s a plus athlete and runner with above-average raw power, projecting as a potential everyday center fielder if his hit tool continues trending up.

Juan Rijo (OF) – MLB ETA: 2031

Age: 17 | Current Level: ROK | Bats: R | Throws: R

Rijo was added to the system as part of the Mariners’ January 2026 international signing class. He’s currently working through extended spring training in the Dominican Republic and remains an unrefined, long-developmental-runway prospect with very little track record to evaluate yet.

Mason Peters (LHP) – MLB ETA: 2028

Age: 22 | Current Level: A | Bats: L | Throws: L

A 2025 fourth-round pick who was a reliever in college, Peters carries the system’s best curveball grade and big stuff that gives him a chance to move quickly. He’s currently with Single-A Inland Empire and profiles as either a fast-moving reliever or a developmental rotation piece, depending on how his command refines.

Michael Morales (RHP) – MLB ETA: 2026

Age: 23 | Current Level: AA | Bats: R | Throws: R

Morales is a kitchen-sink, command-over-stuff righty who doesn’t miss many bats (a sub-7 K/9 in 2025) but has found enough success at Double-A Arkansas to garner a 2026 look in Tacoma. His ceiling is limited, but he profiles as a viable depth starter or bulk reliever thanks to stabilized command over the past two seasons.

Chia-Shi Shen (RHP) – MLB ETA: 2028

Age: 22 | Current Level: A | Bats: R | Throws: R

Shen has dealt with elbow troubles that sidelined him for portions of the 2026 season, with a return expected by midseason. He carries average control grades and projects more as organizational pitching depth than as a true impact arm at this stage.

Po-Chun Lin (RHP) – MLB ETA: 2029

Age: 19 | Current Level: ROK | Bats: L | Throws: L

A stout lefty from Taiwan who has drawn good reviews from scouts in international play, Lin is still working through extended spring training stateside. He’s a name dynasty fanatics are monitoring, given the buzz around his early returns, though he’s very far from a finished product.

Jared Sundstrom (OF) – MLB ETA: 2026

Age: 24 | Current Level: AA | Bats: R | Throws: R

Sundstrom is a versatile, athletic outfielder with enough defensive flexibility to play all three outfield spots, currently holding down a reserve role at Double-A Arkansas. He offers right-handed pop in a part-time capacity and profiles as organizational depth with a path to a bench role in the majors.

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