The Rockies optioned Bird to Triple-A Albuquerque on Saturday.
Bird has struggled to find his footing in the majors this season, accumulating a 6.12 ERA and 1.84 WHIP over 25 innings out of the bullpen. He'll head back to Triple-A in order to right the ship, and his roster spot will be given to Tanner Gordon, who will start Saturday's game versus San Diego.