Giants’ Trade Talks for Castillo Fall Through, Mariners Retain Star Pitcher

SEATTLE, Wash. — The San Francisco Giants explored a potential trade for Seattle Mariners pitcher Luis Castillo earlier this offseason, but negotiations did not result in a deal. As the 2025 season approaches, Castillo is expected to anchor Seattle’s rotation alongside a strong supporting cast.

Reports indicate that the Giants initiated trade discussions after losing Blake Snell to free agency. The franchise sought to bolster its pitching staff but ultimately chose to sign veteran Justin Verlander on a one-year contract instead.

During the offseason, Castillo was frequently mentioned in trade rumors, particularly in connection with the Boston Red Sox. However, the Mariners reportedly were not interested in parting with Castillo for Triston Casas, a top prospect in Boston’s system. Castillo, who turns 32 this year, has an impressive track record, boasting a career ERA of 3.56 after eight seasons in Major League Baseball.

Castillo’s contract, which includes an annual salary of $22.75 million for the next three seasons, also features a vesting option for 2028. His value is underscored by his performance last season, where he recorded a 3.64 ERA with a 24.3% strikeout rate over 175 1/3 innings, marking his sixth consecutive season with an ERA below four.

While the Mariners considered trading Castillo to create payroll flexibility and add talent to their lineup, a high asking price ultimately deterred potential suitors. Seattle’s president of baseball operations, Jerry Dipoto, reiterated the organization’s unwillingness to weaken its rotation.

Several Giants’ prospects were mentioned in the trade talks, including Bryce Eldridge. Reports suggest that the Giants were hesitant to trade their top prospects, showing a focus on long-term talent development.

As the offseason progressed, the Giants secured Verlander, effectively shifting their strategy from pursuing Castillo to maximizing their current roster. Castillo’s continued presence in Seattle’s rotation is notable as he is expected to contribute significantly alongside fellow starters Bryan Woo, Bryce Miller, Logan Gilbert, and George Kirby.

The Mariners aim to improve their offensive performance going into the new season, yet Castillo’s strong pitching will be essential in maintaining competitive games. With an outstanding starting rotation, the Mariners look poised to contend in the league as they prepare for spring training.

Seattle starts its Cactus League play this Sunday against the Arizona Diamondbacks, with Castillo likely to play a pivotal role in their campaign against various competitors.