PEORIA, ARIZONA - FEBRUARY 19: Blas Castano #62 of the Seattle Mariners poses for a portrait at Peoria Sports Complex on February 19, 2026 in Peoria, Arizona. (Photo by Stacy Revere/Getty Images) | Getty Images The Colorado Rockies announced this morning that they have claimed RHP Blas Castaño from the Seattle Mariners. In a corresponding roster move, they have DFA’d LHP Luis Peralta. Bas CastañoThe 27-year-old pitcher is a native of the Dominican Republic signed with the New York Yankees in 2018 and began with their Dominican Summer League team.
He worked his way through the Yankees system until being released on August 8, 2023. Three days later, he was claimed by the Seattle Mariners, starting with their Double-A team. In 2024, he moved between Double-A and Triple-A.
He appeared in 29 games with 26 starts and earned a 4.38 ERA over 125.3 IP. That total included 108 strikeouts. In November of that year, he was added to the Mariners 40-man roster.
Castaño began 2025 in Triple-A Tacoma and on May 23 was promoted to the Mariners. He appeared in one game in which he allowed three runs, on May 28. He spent the rest of the season in Tacoma and began 2026 there.
Last week when the Mariners called up Patrick Wisdom, Castaño was DFA’d. He is more a contact pitcher than a flame thrower. In 2026, he has appeared in six games for Tacoma and has a 1.42 ERA in 6 IP.
According to Baseball Savant, Castaño has a five-pitch mix that includes a cutter (40%), changeup (32%), sweeper (12%), four-seamer (10%), and sinker (6%). Castaño, who still has all of his options, has been sent to Triple-A Albuquerque.Luis PeraltaAfter a stellar 2024, Peralta was unable to find his previous form.In 7.1 IP with the Topes this season, Peralta has a 17.18 ERA (14 ER), including 13 walks and 14 strikeouts in six appearances.Join the conversation!Sign up for a user account and get:Fewer adsCreate community postsComment on articles, community postsRec comments, community postsNew, improved notifications system!Please keep in mind our Purple Row Community Guidelines when you’re commenting. Thanks!