Rockies sign right-hander Diego Castillo He has signed a minor league contract, according to Aram Leighton of Just Baseball Media. The agreement includes an invitation to Castillo, who turns 31 next month, to major league spring camp in Colorado.
Castillo is best known for his work as a regular in the Rays and Mariners bullpens from 2018-22, where the right-hander posted a 3.12 ERA, 28.1% strikeout rate, 50.7% groundball rate, and 50.7 walk rate. 8.9%. Unfortunately, he got off to a very poor start through his first eight games (and 8 2/3 innings) of 2023, leading the Mariners to cut him from the 40-man roster entirely in early May. Castillo spent the remainder of the season in 3A before being selected as a free agent at the end of the season.
The Rangers signed Castillo to a minor league contract last winter and released him at the end of spring training, and the Twins quickly signed him to another minor league contract. During Castillo’s season in Minnesota, he was designated for assignment twice and was taken directly off the 40-man roster. Signed another minor league contract. All of these changes resulted in another season of minimal MLB playing time, with Castillo appearing in 10 games for the Twins and posting a 2.70 ERA in 10 innings.
Control is the biggest issue behind Castillo’s decline, as his walk rate has soared to 14.92% in 84 1/3 innings of Triple-A ball over the past two seasons and 18 2/3 in his brief MLB sample size. Among them, the walk rate is as high as 17.9%. A drop in velocity could also be part of the reason why Castillo struggled in 2023, although his fastball velocity increased from 93.8 mph in 2023 to 95.9 mph in 2024.
Castillo’s prime years are behind him, so it makes sense that the team would still want to try out the veteran right-hander. For the Rockies in particular, if Castillo can earn himself a spot on Colorado’s active roster, his ability to keep the ball on the ground could prove useful in the thin air at Coors Field .
