Betancourt was put on the DL on July 20 with appendicitis. The 38-year-old closer is 2-3 with a 3.16 ERA and has converted 15 of 16 save opportunities.
Before the Rockies faced the Orioles on Saturday, Colorado manager Walt Weiss said, ""Rafe is ready to go. We're going to make sure he's mentally ready to go and then throw him into the fire."
Rex Brothers served as closer in Betancourt's absence.
Colorado made room for Betancourt by optioning right-hander Manuel Corpas to Triple-A Colorado Springs.
Corpas pitched in 19 games for Colorado this season after beginning the year with Colorado Springs. He was 1-2 with a 4.50 ERA.