The Rockies searched with a right-hander Blas Castaño waivers from the Mariners, according to announcements from both clubs. The righty was designated for assignment by the Mariners last week. The Rockies optioned him to Triple-A Albuquerque. In a corresponding movement, to the left Luis Peralta selected for assignment.
Castaño, 27, was originally signed internationally by the Yankees out of the Dominican Republic. He was released in the summer of 2023 and was picked up by the Mariners. He impressed for his new club in 2024, posting a 4.38 earned run average in 125 1/3 minor league innings, spending most of that in the Pacific Coast League. He was added to the 40-man roster in November 2024 to prevent him from reaching major league free agency.
He spent the last year-and-a-half as a deep arm for the Mariners without much need. He has only made one major league appearance, a three-inning relief appearance in May of last year.
He threw 126 2/3 innings for Triple-A Tacoma last year with a 5.19 ERA, in unfriendly PCL terrain. His 17.8% strikeout rate and 9.3% walk rate weren’t too strong but he did strike out on 46% of balls in play. So far this year, he has been coming out of the bullpen, throwing 6 1/3 innings in six games for the Rainiers. His 1.42 ERA in that small sample looks good but his strikeout and ground ball rates are about the same as last year.
The Mariners took him off their roster but the Rockies will give him a shot. They may be attracted to the diversity of his voice, something that seems to have become a favorite of the organization. Statcast classifies him as a five-hit guy. He doesn’t bowl his four-seamers regularly, he leads with his chisel, in addition to the slider, cutter and changeup. His fastball and sinker average around 94 miles per hour, cutter around 90, changeup in the high-80s and slider in the low-80s.
The Rockies could stretch him back or stay in a relief role. They need to bend either way. They had a 5.99 ERA as a team last year, worst in the majors. They have a 4.40 ERA so far this year, which puts them in the bottom ten of MLB’s clubs, but by a much smaller number of games. Whether he works as a starter or reliever, the Rockies can keep him in Triple-A until needed. He can still be selected this season and next season.
Peralta, 25, was acquired from the Pirates in a 2024 deadline deal Jalen Beeks to Pittsburgh. Peralta, younger brother of Freddy Peraltahe showed some potential during that trade but his stock has dropped.
He first played a big role for Pirates. Between the Bucs and Rockies, he threw a minor league 47 2/3 innings in 2024 with a 0.94 ERA. His 11.2% walk rate was high but he struck out 40.1% of opponents and struck out at a 48.8% clip. He also posted a 0.73 ERA in his first 12 1/3 big league innings.
2025 was a big step back, as he posted an ERA over 9.00 in both the majors and minors. His 28% strikeout rate in Triple-A is still good but down significantly, while his walk rate is up to 15.4%. In the majors, his 17.8% walk rate was worse than in the minors and higher than his 15.8% strikeout rate, both of which were worse than average. So far this year, he has thrown 7 1/3 innings in Triple-A with a 31.1% strikeout rate but a 28.9% walk rate and 14 earned runs allowed.
Those issues took him off Colorado’s roster. DFA limbo can last for up to a week. The waiver process takes 48 hours, so the Rockies could take as long as five days to evaluate trade interest. His recent numbers are obviously not great but maybe other clubs see a way to get him back to the top form he showed in 2024. He still has options and could be sent to the minors if a club can get him in the coming days.
Photo courtesy of Jayne Kamin-Oncea, Imagn Images
