The trade market for Seattle Mariners ace Luis Castillo continues to heat up, with the San Francisco Giants emerging as strong contenders, per Susan Slusser of the San Francisco Chronicle. Castillo has been one of the most sought-after pitchers this offseason, with prior links to the Boston Red Sox, Chicago Cubs, New York Yankees, and Baltimore Orioles.
The Giants, who have already made headlines by signing Willy Adames to a franchise-record deal, are reportedly looking to bolster their rotation further. Castillo would be an ideal fit, offering the reliability and strikeout potential they need to strengthen their starting staff.
San Francisco’s rotation currently includes Logan Webb, Robbie Ray, Hayden Birdsong, and Kyle Harrison, but adding Castillo would give them a true ace to lead the staff. Castillo, under contract through 2027 with a reasonable $24 million annual salary, provides high-end production, making him one of the most valuable pitchers potentially available this offseason.
With several teams in the mix, competition for Castillo’s services will be fierce. Whether the Giants can offer the Mariners the right combination of prospects and major-league-ready talent remains to be seen, but the move would signal their commitment to building a playoff-caliber roster for 2025.
SF Giants Join the Mix of Potential Luis Castillo Trades
The Giants are aiming to improve their starting rotation in 2025, and signing the 32-year-old Dominican veteran would help cement it. Castillo and innings eater/starter Logan Webb would lead a superb Giants rotation. Castillo is an ace who demonstrated his best qualities during the 2023 season with the Mariners. His excellent figures that year were a 27.3% strikeout rate, a 3.34 ERA, and a.218 batting average against him, which was his lowest mark with Seattle and fifth-lowest of his career. He also reached 1,000 strikeouts against the Oakland Athletics and had a perfect game until the eighth inning against the Colorado Rockies.
Castillo’s pitching repertoire includes a four-seam, slider, sinker, and changeup. According to Baseball Savant, he uses the four-seamer the most (45.3%). In 2024, the fastball reached approximately 96 mph. Last season, Castillo went 11-12 with a 3.64 ERA, 175 strikeouts, and a 1.169 WHIP. In December, MLB analyst Jon Morosi referred to Castillo as “one of the very best arms in the American League.” But what would it take for the Giants to get Castillo? Moving any minor leaguers aside from the Giants’ top prospect Bryce Eldridge would make sense. In addition, the Mariners may consider a package offer involving such names as Tristan Beck, Casey Schmitt, Carson Whisenhunt, and Wade Meckler, all up-and-coming major leaguers.
