When healthy, Castro can throw a four-seam and two-seam fastball in the 95-97 mph range. Castro, who is in his final year of Minor League options, was a candidate to make the Rockies' squad before this spring, but he could not right himself once flaws crept into his delivery during an outing.
Castro began 2015 as the Blue Jays' closer, and he went 0-2 with a 4.38 ERA and four saves in 13 games. He spent time in the Minors before being sent to the Rockies, for whom he finished the year with five relief appearances (0-1, 10.