Interim manager Tony Mansolino said after Tuesday's 6-3 loss to the Guardians that O'Neill is dealing with general soreness, Matt Weyrich of The Baltimore Sun reports.
O'Neill was held out of the lineup Tuesday, and his injury could explain why the Orioles recalled Dylan Carlson from Triple-A Norfolk. The 30-year-old O'Neill missed more than a month earlier this season with a shoulder injury and is slashing just .152/.222/.303 since returning from the injured list.