 For the rest of the 2013 season with the Red Sox, Thornton's playing time was limited due to an oblique strain but made 20 appearances out of the bullpen going 0–1 with a 3.52 ERA.Overall in 2013, combined with both teams, Thornton made 60 total relief appearances going 0–4 and a 3.74 ERA.The Red Sox finished 97–65, making it to the postseason and eventually winning the World Series over the St. Louis Cardinals.