Seattle Mariners Top 10 Prospects For 2026 Fantasy Baseball

Format = Position Player | Age on 4/1/2026 | Highest Level Played | Estimated Time of Arrival 

1. OF Lazaro Montes | 21 | AA | 2027

At 6’5” 215 pounds, Montes has slimmed down without sacrificing power as he’s climbed the organizational ladder. In 131 games split almost evenly between High-A and Double-A, the big lefty smashed 32 home runs, stole seven bases and slashed .241/.354/.504 with a 29 percent strikeout rate. The strikeouts have invited a fair share of doubters, but I think Montes will make enough impact on contact to become a mainstay in fantasy lineups. 

2. SS Colt Emerson | 20 | AAA | 2026

Seattle snagged Emerson out of high school at the 22 spot in the 2023 draft. A left-handed hitting middle infielder at 6’1” 195 pounds with excellent hands in the batter’s box, he came roaring out of the gate in his draft season but battled injury in 2024, missing two stretches and playing 70 games total. 2025 was a year of water finding its level. Emerson’s hit tool carried him all the way to Triple-A, where he batted .364 with two home runs in six games to close out the season. Roster resource lists Ben Williamson as the starting third baseman, and while that might be true for spring training, Emerson will elbow his way into the picture sooner or later. 

3. LHP Kade Anderson | 21 | NCAA | 2027

The third overall pick in the 2025 draft, Anderson went 12-and-1 for LSU as a sophomore, recording a 3.18 ERA and 1.06 WHIP with a whopping 180 strikeouts in 119 innings. Wielding a dominant and deceptive fastball alongside three plus off-speed pitches he can throw for strikes, Anderson was way too much for most college hitters. Seattle rested him after the draft, but he has the look of a fast mover who can help this team during its current contention cycle. 

4. RHP Ryan Sloan | 20 | A+ | 2027

At 6’5” 220 pounds, Sloan is a power pitcher who flushes hitters with a triple-flow of splitter, slider and fastball. The 55th overall pick in the 2024 draft, he recorded a 3.73 ERA and 1.16 WHIP with 92 strikeouts against just 15 walks in 82 innings across two levels. His upside is perhaps the highest on this list relative to cost considering the skillset and the setting. 

5. SS Felnin Celesten | 20 | A | 2028

A switch hitter who signed for $4.7 million in 2023, Celesten has lost time to injury but still managed to impress during his brief professional career. In 93 Low-A games, he slashed .285/.349/.384 with five home runs and 20 stolen bases, earning himself an 11-game debut with High-A to close out the season, where he’ll probably open 2026. From both sides, Celesten features a steep bat path geared for lift. He could unleash something of a surprise power season if it all comes together with man strength in his early 20’s. 

6. SS Michael Arroyo | 21 | AA | 2027

Listed at 5’10” 160 pounds, Arroyo doesn’t make many jaws drop when he steps off the bus, but he’s always impressed plenty between the white lines. His 56-game stretch in Double-A wasn’t the stuff that fantasy dreams are made of, but his slash line of .255/.376/.341 with two home runs was good for a 123 wRC+ in a depressed setting for offense. In 121 games across two levels, he struck out 18.7 percent of the time with a 12.4 walk rate and a 139 wRC+. His ETA is listed at 2027 here, but he could push that pretty easily into this season if the need arises. 

7. OF Jonny Farmelo | 21 | A+ | 2028

A left-handed hitter at 6’2” 205 lbs, Farmelo went 29th overall in the 2023 draft and drew rave reviews right away. The team sent him to Low-A, and Farmelo slashed .264/.398/.421 with four home runs and 18 stolen bases. The club knew he’d be impressive from a speed and power perspective, but the patience and impact in Low-A were probably both pleasant surprises. A torn ACL ended his season early or he might’ve played his way to the top of this list. He got back onto a High-A field late in 2025, slashing .230/.318/.460 with six home runs and two steals in 29 games. He also struck out 29.5 percent of the time. Makes perfect sense to me that his first month back in action wouldn’t generate his best statistical output. Might be a buy-low opportunity. 

8. RHP Jurrangelo Cijntje | 22 | AA | 2026

Cijntje is a switch-pitcher with legitimate upside from both the right and left sides, touching 99 with the heat and 91 with a slider from the right side and living in the low 90’s from the left, where he features a solid sweeper. Seattle selected him 15th overall in the 2024 draft after he pitched two seasons in the SEC for Mississippi State. In 108.1 innings across two levels in 2025, he recorded a 3.99 ERA and 1.22 WHIP with 120 strikeouts against 51 walks. If he were being developed as a righty only, he’d move up a couple spots on the lists. As is, I’m not sure what to do with him. Is he going to learn multiple ways to attack left-handed hitters as a right-handed pitcher? Or is the back-and-forth going to condemn him to some kind of hybrid swingman role? 

9. OF Yorger Bautista | 18 | DSL | 2030

A toolsy lefty at 6’1” 175 pounds, Bautista signed for $2.1 million with the 2025 international class and spent the season in the Dominican Summer League, slashing .223/.326/.404 with seven home runs and a 29.8 percent strikeout rate. That’s a lot of swing-and-miss for a big-money signing, but Bautista buys himself a lot of runway with his easy plus power and speed. 

10. C Luke Stevenson | 21 | A | 2027

Seattle selected Stevenson with the 35th overall pick in 2025 after he hit 33 home runs in 125 games at North Carolina. He controlled the strike zone well as a collegiate and carried that over to Low-A for his 20-game debut after the draft, where he walked (23%) more than he struck out (19%) while slashing .280/.460/.400 with a 154 wRC+. Where’s he gonna play in this organization? Well, I’m not sure he will because he’s a good defender, and Seattle will likely  be looking to add at the trade deadline this year. 

Thanks for reading!