Ross suffered two concussions during the 2013 season and spent over two months on the disabled list; however, his health returned and he played a key role in Boston's run to the World Series championship over the St. Louis Cardinals that year, starting in four games during the series and driving in the game-winning run with an RBI double in Game 5. He was also behind the plate to catch the series-clinching out in Game 6 when Koji Uehara struck out Matt Carpenter.