Mariners Option Castaño, González, Danner to Triple-A Tacoma in Spring Cuts

The Seattle Mariners trimmed their spring roster by sending right-handers Blas Castaño, Domingo González, and Hagen Danner to Triple-A Tacoma, with left-hander Josh Fleming reassigned to minor league camp. The moves continue a wave of spring adjustments as Seattle shapes its roster ahead of the season.

Castaño, who turns 28 in September and carries a 5.19 ERA across 126.2 innings with Tacoma in 2025, had a rough spring audition before the cuts. He allowed five runs, four earned, in just two innings of Cactus League work, a performance that left little room for debate about his assignment. The 5-foot-10 right-hander from Espaillat, Dominican Republic was added to Seattle's 40-man roster on November 4, 2024, protecting him from minor league free agency, but the rotation spot he was chasing will have to wait.

His path to the majors has already taken one detour and a brief breakthrough. Castaño made his MLB debut on May 28, 2025, entering the final three innings of a loss to the Washington Nationals and allowing three runs, including a home run by Robert Hassell III that marked Hassell's first career big-league blast. He was optioned back to Tacoma the following day and spent the remainder of that season there, finishing with an 8-6 record, 5.19 ERA, 97 strikeouts, and a 1.39 WHIP in 29 games. Seattle recalled him again on September 29, 2025, before a series of roster moves through October ultimately led to another option to Tacoma on March 11, 2026.

His 2024 numbers across Double-A Arkansas and Triple-A Tacoma showed similar inconsistency: a 5-8 record and 4.38 ERA with 108 strikeouts across 125.1 combined innings. At Tacoma specifically that year, he posted a 5.13 ERA and 1.41 WHIP.

Danner's option to Tacoma alongside Castaño was confirmed in the Mariners' official spring training roster announcement. Fleming, a left-hander, received a reassignment to minor league camp rather than an option, a distinction that reflects different roster mechanics. González's option to Tacoma was included in the team's announced moves.

Castaño remains on Seattle's 40-man roster and figures to be a depth arm for the Rainiers. His next scheduled appearance comes when Tacoma travels to Reno on March 27.