Smith was recalled from Triple-A Albuquerque on Thursday.
Smith has had brief stints with the big-league club this season and will rejoin the Rockies' bullpen since active rosters expanded to 28 players Thursday. He's posted a 3.09 ERA and 1.09 WHIP in 35 innings over 32 appearances at the Triple-A level this year but should serve mainly as a middle reliever now that he's back in the majors.