The Orioles placed Eflin (elbow) on the 15-day injured list Wednesday.
Eflin was lifted from his start Tuesday against the Rangers due to right elbow discomfort. He's set to undergo an MRI on Wednesday, at which point more will be known about how long he will be sidelined. Dean Kremer is likely to be called up from Triple-A Norfolk to take over Eflin's spot in the Baltimore rotation.