Not to be confused with the current Seattle Mariners ace, Luis Castillo, they are adding former MLB relief pitcher Luis F. Castillo to a minor league deal with an invite to MLB Spring Training.
Castillo, 29, was born in Fantino, Dominican Republic, signing with the Arizona Diamondbacks and making his minor league debut at 17. He would spend ten seasons in their minor league system, reaching Triple-A for the first time during the 2021 season. The DBacks would release him after the 2021 season.
He would sign a minor-league deal for 2022 with the Detroit Tigers, beginning the year in Triple-A. Castillo made his MLB debut in August, pitching in three games during the year, only allowing two hits throughout three and two-thirds innings, striking out four batters, and never allowing an earned run. He was outrighted off the Tigers roster and elected free agency at season‘s end.
For 2023, Castillo signed with the Chiba Lotte Marines of Nippon Professional Baseball (NPB). He would split his time between the Pacific and Eastern Leagues in Japan, throwing in a total of 21 games, going 4-5, posting a 2.83 ERA, striking out 73 batters across 89 innings of work. For 2024, he signed with the Orix Buffaloes. He would get an opportunity in their starting rotation, where in 16 starts, he would go 3-5 with a 2.93 ERA, striking out 74 batters and walking 18 in 95.1 innings pitched.
Castillo is set to compete for a spot in the Mariners rotation or could be seen as a long-innings reliever during Spring Training. The Mariners have only made a few moves this offseason, most notably signing Colombian infielder Donovan Solano. It will be intriguing to see what Castillo will bring to the table this March.
