The surgery for a torn ulnar collateral ligament in the thumb was performed by Dr. Donald Sheridan in Arizona.
McDonald, 31, was a pleasant surprise for Boston in 2010, making the most of an opportunity to play when several Sox players were injured. McDonald batted .270 with nine home runs and 34 RBIs in 117 games.
According to the Boston Globe, McDonald suffered the injury during Spring Training and played with it all year. The Globe reported that Boston's medical staff didn't know of the injury until McDonald's end-of-year physical.
Doug Miller is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.