Needing immediate help to prop up a sagging bullpen, and with an eye toward their future, the Rockies designated veteran reliever Rafael Betancourt for assignment Sunday.
Betancourt, 40, has pitched his last game for the Rockies and admitted that retiring from baseball is a possibility.
The Rockies also optioned right-handed reliever Justin Miller to Triple-A Albuquerque, recalled right-handed reliever Jairo Diaz from Triple-A and selected the contract of right-handed reliever Simon Castro.
Both Castro and Diaz are available for Sunday afternoon's game against the New York Mets.
The Rockies also reinstated right-handed reliever Brooks Brown from the 15-day disabled list and optioned him to Albuquerque.