Mariners set to add slugging OF Lazaro Montes from Cuba, with a September call-up looming

The Seattle Mariners are expected to call up Cuban outfield prospect Lazaro Montes in the coming days, according to multiple reports, a move aimed at injecting more power into the Mariners’ late-August and early-September lineup. The reports indicated Montes is already in transit to Boston, suggesting the organization is working to have him available during the Mariners’ road stretch rather than waiting for a later week.

The timing matters because MLB’s September roster rules allow clubs to increase the number of eligible players, giving teams a broader set of options for games through the month. In the reporting on Sunday, it was described as a roster expansion to 28 for September call-ups, which helps explain why the promotion is being discussed now rather than earlier in the season.

As for how soon Montes could appear, the same reports emphasized that he is in transit but is not necessarily expected to be activated immediately for the first game of the Mariners’ series in Boston. That distinction is typical of call-ups that are announced in advance of travel, where a player can be added to the active roster by rule yet still be managed with game-day readiness, lineup fit, and travel logistics in mind.

From a baseball perspective, the Mariners’ interest in Montes is rooted in the profile implied by the way he is being described: a slugging outfield prospect. Adding a power-oriented bat at this stage of the season can be a pragmatic choice, particularly when a team is looking to create margin in close games. In many cases, a September call-up also gives a front office its first close look at how a prospect’s approach translates against major league pitching at game speed, under normal lineup and bullpen pressure.

The move also carries an obvious opponent-specific layer. Because Montes was described as traveling to Boston, his first major league exposure may come in a high-visibility setting against a familiar American League opponent rather than a quieter home series. The Mariners and Red Sox have separate team identities and pitching tendencies, so managers often use early at-bats in a new environment to determine whether a prospect should be used as a full-time option, a late-inning swing role, or a matchup-driven bat.

For Mariners fans, the immediate question will be whether Seattle treats the call-up as an evaluation opportunity or as a functional part of the active lineup through the series. For the player, the question is whether the power for which Montes is being scouted shows up quickly enough to earn additional opportunities, especially if the coaching staff sees defensively how he fits in outfield rotations and late-game matchups.

This reporting has not been presented as an official Mariners transaction release in the information available here, so the most important caveat is confirmation and activation details. Even with a call-up expected, the day-to-day roster decisions can change based on readiness, travel timing, and game-day strategy, so the best next checkpoint is the Mariners’ official roster communication and the game-day active lists once the series gets underway.