On August 31, 2013, McDonald was traded to Boston Red Sox in exchange for minor league pitcher Nefi Ogando. As McDonald was acquired prior to September 1, he was eligible to play in the postseason. He appeared in 6 games for the Red Sox in the regular season, hitting .250 in 8 at-bats. McDonald was not included on the postseason roster, but following the Red Sox' 2013 World Series victory, was awarded a World Series ring.