Bailey was placed on the DL on May 28 with a sprained right shoulder. It was his second stint on the disabled list; he was sidelined at the outset of the season with an impingement in the same shoulder.
Heading into Sunday's start against the Orioles, the 25-year-old Bailey was 3-1 with a 3.00 ERA in five games this season.
To open up a spot on the 25-man roster, the Reds optioned right-hander Carlos Fisher to Triple-A Louisville. Fisher was 0-3 with a 3.71 ERA in 10 appearances, all in relief.