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.
The 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.
After 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.