The Red Sox reinstated Whitlock (elbow) from the injured list Saturday.
Whitlock will return to Boston's bullpen after spending close to the minimum amount of time on the injured list due to right elbow inflammation. The 30-year-old reliever never made any rehab appearances in the minors but still figures to immediately slot back in as the Red Sox's top setup man for closer Aroldis Chapman. Wyatt Olds was optioned to Triple-A in a corresponding move.