Miley was placed on the 15-day DL on Friday with a left shoulder impingement.
It is unclear how serious the injury is, but Miley was likely in danger of losing his spot in the rotation at some point in the near future anyway, as he has a career-worst 5.28 ERA and his 4.85 FIP is his worst mark since 2011. Miley was scheduled to start Saturday's game against the Red Sox and Adrian Sampson, who is with the team Friday although not officially added to the 25-man roster yet, is expected to step into the rotation for the time being.