Phillips was recalled from Triple-A Norfolk on Tuesday.
Phillips made his big-league debut last season, throwing 11.2 innings for the Braves and Orioles. His results were very unimpressive, as he recorded a 13.11 ERA with an 8:10 K:BB. He'll likely fill a low-leverage role in the Orioles' bullpen while he remains with the team. Nate Karns was placed on the 10-day injured list with a right forearm strain in a corresponding move.