Mariners to Promote 38-Homer Top Prospect for MLB Debut vs. Red Sox

PEORIA, ARIZONA - FEBRUARY 24: Lazaro Montes, the 38-home run top prospect for the Seattle Mariners, takes the field during a spring training game against the Chicago White Sox on February 24, 2026 in Peoria, Arizona. (Photo by Mike Christy/Getty Images) The Mariners have announced that outfielder Lazaro Montes will be promoted to the MLB roster upon its expansion to 28 players on September 1.

According to Ryan Divish of The Seattle Times and MLB sources, Montes, who is 21 years old, will be added to the MLB roster when they expand their roster on Tuesday. Montes, who has a .247/.365/.556 batting average with 38 home runs and a 137 wRC+ between Double-A Arkansas and Triple-A Tacoma, is currently ranked as the Mariners’ No. 5 prospect and No. 56 prospect on MLB Pipeline.

The Mariners’ postseason hopes have faded following a sweep by the Toronto Blue Jays, prompting a shift in focus to their 2027 roster. The promotion of Montes comes as Seattle has already promoted top prospect Kade Anderson, indicating the start of a youth movement. Montes will not participate in the series opener against the Boston Red Sox on September 1, although he may still travel with the team.

Randy Arozarena, the left fielder, is expected to reach free agency and could be out of Seattle’s budget. It is unclear where Montes will fit in the lineup, as Seattle already has Arozarena, Julio Rodriguez, and Taylor Ward in the outfield. Dominic Canzone is the primary designated hitter against right-handed pitching. The roster move could indicate Seattle’s potential waiver claim on Ward, while Arozarena will not be put on waivers due to his qualifying offer candidacy.

The promotion also impacts the Mariners' 40-man roster decision, speeding up the process by 10 weeks. If Montes excels during the season, it could alter the organization's plans for him in 2027, potentially moving him into Arozarena’s outfield spot or as the designated hitter.