Arizona Fall League Preview: Seattle Mariners
By Taylor Anderson ·
Eight Seattle Mariners prospects join the Peoria Javelinas for the 2026 Arizona Fall League. The group leans heavily on arms, with five pitchers carrying questions worth answering in the desert, but the bats draw the most attention. A catcher who changed organizations at the deadline and hit 31 home runs across three levels headlines the group, while a corner infielder coming off a Player of the Month August gets a chance to push his case for Double-A. Here's the full breakdown.
Boston Smith Slugged His Way Through Three Levels
Boston Smith is the name in this group. The 23-year-old catcher, a sixth-round pick by Washington out of Wright State in 2025, was traded to the White Sox at the end of spring training and then came to Seattle in the Luis Castillo deal at the Trade Deadline. Along the way he hit 31 home runs across four stops while drawing 97 walks in 493 plate appearances. That combination of patience and power is rare at any level, and he did it while climbing from Single-A to Double-A Arkansas. His combined .274/.424/.566 slash line and 19.7 percent walk rate describe a hitter who waits for something to drive and puts a charge into it when he finds it.
The defensive picture is what makes this AFL stint important. Smith did not arrive in pro ball with a long track record behind the plate, and while he caught in most of his games this year, there's little public evidence on his receiving, blocking or throwing. He also played some left field. Peoria will give evaluators a concentrated look at whether the catching defense is playable or whether a position change is coming. If he can catch, the offensive profile projects as at least a second-division regular. If he can't, his 29.2 percent strikeout rate becomes a bigger issue, because the offensive bar rises considerably at a corner or DH spot.
At Arkansas specifically, he posted a 15.8 percent walk rate and a .516 slugging percentage in 33 games, with nine home runs. The swing-and-miss is a concern against better breaking balls, but the walk totals suggest he's not simply swinging through counts. Watch how he handles quality stuff in the AFL, and watch the receiving as closely as the box score.
Brandon Eike Won August, Now He Needs October
Brandon Eike spent the full season at High-A Everett and put together a profile worth watching: 24 home runs, 29 doubles and a .295/.357/.535 line in 111 games. That came a year after he hit .208 at the same level. He was named Northwest League Player of the Month for August, so the season finished on an upswing rather than fading. At 25 and still at High-A, he can use the AFL as a showcase for a Double-A case in 2027.
Eike split his defensive time between first base and third base this year. With a 7.8 percent walk rate and a 24.5 percent strikeout rate, the approach sits in an average-to-aggressive range without being a major red flag. He'll need to show he can handle secondary pitches from upper-level arms before the org pushes him forward, and Peoria offers better pitching than the Northwest League did.
Reid Easterly Made a Case for a Bullpen Spot
Reid Easterly, a 24-year-old lefty who signed as an undrafted free agent out of Duke in 2025, was the Mariners' Minor League Reliever of the Month for July and backed it up with a full season that holds up: 77 strikeouts in 66.1 innings at Everett, a 5.6 percent walk rate and a 3.39 ERA. His 27.1 percent strikeout rate and low walk rate describe a pitcher who attacks the zone and gets swing-and-miss without a control cost.
His Fall League opener on Oct. 3 was rough (five runs while getting one out), but the full Everett body of work is the relevant data. The question in the desert is whether he can repeat that command against hitters a level or two above what he saw all year.
Adam Smith's Two-Level Split
Adam Smith, 26, took a winding road to this roster. A former Padres draft pick who spent two seasons in the Red Sox system, he opened 2026 in the independent Atlantic League before Seattle bought his contract in May. His season split cleanly: excellent at Everett, much harder at Double-A Arkansas. At Everett he posted a 1.67 ERA across 16 appearances, with a 28.7 percent strikeout rate and a 4.6 percent walk rate in 27 innings. At Arkansas the ERA climbed to 4.76, the strikeout rate dropped to 15.7 percent and the walk rate doubled to 9.4 percent. The combined line, a 3.25 ERA with a 21.7 percent strikeout rate, is serviceable, but the gap between levels is the story.
The AFL gives him extended exposure to better hitters after a season that showed he can be effective but still needs to prove the High-A performance wasn't his ceiling. For an older reliever, the margin for patience is tighter.
Ty Cummings and the Home Run Problem at Double-A
Ty Cummings is a sidearm right-hander whose delivery creates deception and ground balls. Seattle acquired him from Tampa Bay in late April for Casey Legumina, and after starting 19 games at Double-A in 2025, he worked exclusively in relief this year. The results were a problem: 12 home runs allowed in 56.2 innings at Arkansas, a 6.04 ERA and a 17.4 percent strikeout rate. The low strikeout rate is the bigger concern, because a contact-management profile needs enough swing-and-miss to offset the hard contact.
His combined Double-A ERA, including a few outings with the Rays' affiliate, was 5.66 in 62 innings. The sidearm delivery and ground-ball potential remain viable tools, but the AFL is a chance to work on command and zone consistency after a rough season. Without better command and more swing-and-miss from his slider, he profiles as depth.
The Rest of the Group: Schapira, Geraldo, Ellis
Calvin Schapira, a 26-year-old lefty reliever at Everett, had the strikeouts (63 in 44.1 innings, a 30.3 percent strikeout rate) to stay interesting, but a 13.0 percent walk rate and 20.1 pitches per inning undercut the swing-and-miss upside. His ERA settled at 4.06. The AFL question is simple: can he throw more strikes against better hitters without his contact allowed spiking?
Jose Geraldo, also 26 and at Everett, offers a similar profile: 54 strikeouts in 47 innings, a 26.5 percent strikeout rate and an 11.3 percent walk rate. His 4.21 ERA and seven home runs allowed in 47 innings are concerns. He has enough swing-and-miss to warrant fall reps, but the command and fly-ball issues are the barriers to the next level.
Matthew Ellis, 26, spent the year at Everett, where he caught 19 games, played 19 at first base and served as the DH in the rest. His .247/.376/.470 line with 17 home runs across 76 games shows enough power and patience (a 15.9 percent walk rate) to profile as a useful bat, but a 28.9 percent strikeout rate and questions about his catching mirror, at lower stakes, some of what Boston Smith faces. His approach is patient enough to project some value; the position question remains open.
Bottom Line
Boston Smith is the player Seattle will watch most closely this fall. His production across three levels was strong enough that the Mariners need to know what they have defensively. A catcher who hits like that is a genuine asset; a first baseman or DH with a 29 percent strikeout rate is a much harder roster fit. Peoria is where the catching grade either gets more credible or the Mariners start planning for him at another position.