The Boston Red Sox today declined the 2014 contract option on left-handed pitcher Matt Thornton. As a result, he will become a free agent.

Executive Vice President/General Manager Ben Cherington made the announcement.

Thornton, 37, went 0-1 with a 3.52 ERA (6 ER/15.1 IP) in 20 appearances for the Red Sox, including 15 scoreless outings, after being acquired from the Chicago White Sox on July 12. Between both clubs he totaled an 0-4 record with a 3.74 ERA (18 ER/43.1 IP) in 60 games out of the bullpen this season. The 10-year major league veteran is 32-42 with a 3.53 ERA (223 ER/568.1 IP) in 606 career appearances, including one start.