Johnson was held out of Monday's practice and is expected to have an MRI performed on his right shoulder, Gary Washburn of the Boston Globe reports.

EDGE Analysis

Johnson moved back into the starting lineup for Game 3 on Sunday, but eventually hurt his shoulder, which limited him to a total of nine minutes. The Celtics are going to have Johnson go in for an MRI to make sure he's not dealing with something more serious and that should give us a better indication for how long it could keep him on the sidelines. For now, consider Johnson questionable going into Game 4 on Tuesday, with another update likely coming following his MRI.