Garcia was optioned to Triple-A Albuquerque on Wednesday.
He gave up six runs in five innings Tuesday in a spot start against the Red Sox that represented his big-league debut. Garcia is one of the Rockies' better pitching prospects, but he's probably not good enough to have success in Coors Field with any consistency. Sam Howard was recalled in a corresponding move. It's possible Garcia could get a few more spot starts when rosters expand in September.