O'Neill has been sent back to Boston to receive imaging on his sore right knee, Ian Browne of MLB.com reports.

EDGE Analysis

Red Sox manager Alex Cora indicated that it's more for peace of mind than a worry that O'Neill is dealing with a significant injury, but it's still not an encouraging development. O'Neill is missing a third straight start Tuesday, and it's safe to assume he won't play in the series finale in Baltimore on Wednesday, either. The Red Sox will begin a homestand Thursday versus the Tigers.