In another move to add young arms with options to a system that’s now filling up with them, the Orioles acquired reliever Miguel Castro from the Colorado Rockies for future considerations Friday.

Castro, 22, was a big piece in the Rockies’ deal that sent shortstop Troy Tulowitzki to the Toronto Blue Jays, but hasn’t found his footing in the Colorado bullpen in the two seasons since. In 37 games at the major league level between the Blue Jays and Rockies, Castro has a 6.12 ERA and a 1.67 WHIP. In the minors, however, he has posted a career 3.08 ERA with a 1.126 WHIP.

Castro is in his final season with a minor league option, and was designated for assignment by the Rockies despite his upside with a 97 mph fastball and a hard slider. The Orioles optioned him to Double-A Bowie.

To make a spot on the 40-man roster, the Orioles designated right-hander Joe Gunkel for assignment. Gunkel was one of two players added to the roster for the purposes of protecting them from the Rule 5 draft in November after he posted a 4.02 ERA in 28 starts last year between Bowie and Triple-A Norfolk.