The Seattle Mariners 40-man roster is now complete.

Monday marked the deadline for several different types of trades for MLB teams. This was the deadline for players or teams to exercise their options, for teams to extend qualifying offers to eligible players and for clubs to activate players from the 60-day injured list and place them on the roster. list of 40 players.

The Mariners completed two of three trades on Monday.

Seattle had no outgoing free agents eligible to receive a qualifying offer, meaning the only trades to be made were activating three players (Sam Haggerty, Matt Brash, Jackson Kowar) from the injured list and waiting to find out if outfielder Mitch Haniger had invoked his $17.5 million player option.

Aside from a confusing few hours where there was no confirmation as to whether Haniger exercised his player option after the 2 p.m. PT deadline, there was virtually nothing unexpected on Monday for the Mariners.

Except for one thing.

Seattle selected 26-year-old pitcher Blas Castano from the team’s Triple-A affiliate on Monday. The addition of Castano along with Kowar, Haniger, Brash and Haggerty rounded out the team’s 40-man roster.

Francys Romero initially reported the roster change.

Castano played 29 games for the Rainiers and Double-A affiliate Arkansas Travelers in 2024 and started 26 games. He posted a 4.38 ERA with 108 strikeouts in 125.1 innings pitched.

Castano was originally signed by the New York Yankees as an international free agent in the Dominican Republic on June 1, 2018. He was released by the organization on August 8, 2023 and signed by the Mariners on August 11, 2023.

Castano is an interesting choice for the 40-man roster, especially since he has primarily been used as a starting pitcher since joining the Seattle organization. Given the Mariners’ elite starting rotation, this could indicate that the team wants to take a look at Castano in spring training. This could also show that the team anticipates Castano being used as a reliever in the future.

This also could have been a way for the team to avoid Castano being available in December’s Rule 5 draft.

Whatever the reasoning, it probably won’t be long before Seattle fans get a good look at Castano.

HANIGER OFFICIALLY EXERCISES PLAYER OPTION: After several hours of confusion, it has been confirmed that a Seattle Mariners outfielder has invoked his 2025 player option. CLICK HERE

FORMER MARINERS OUTFIELDER JOINS MARINERS’ TOP RIVAL: A 2024 World Series champion and former Seattle Mariners outfielder was acquired Monday by the team’s biggest division rivals. CLICK HERE

RALEIGH AND MOORE JOIN THE PRESTIGIOUS LIST OF GOLD GLOVE FRANCHISE HONORS: Seattle Mariners catcher Cal Raleigh and infielder Dylan Moore became the latest Gold Glove winners in a list that includes several team legends and Hall of Famers. CLICK HERE

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