Castro tossed a scoreless inning in the Rockies' loss to Pittsburgh on Monday afternoon.
After spending a month at Triple-A, Castro has come back to fire a pair of scoreless frames for the Rockies. With a 9:2 K:BB over eight innings, he's quickly becoming one of the more reliable options in the Colorado bullpen. As a result, it would hardly be surprising to see him used in higher-leverage situations in the coming weeks.