Kelly, 27, made 25 starts for Boston in 2015, his first full season in the Red Sox organization, going 10-6 with a 4.82 ERA (72 ER/134.1 IP). He set career highs in wins (tied), starts, innings pitched, strikeouts (110), and strikeout rate (7.4 SO/9.0 IP). The right-hander posted a 3.77 ERA (25 ER/59.2 IP) in his last 11 appearances following a four-start stint with Triple-A Pawtucket. He won eight consecutive starts from August 1-September 9, the longest streak by a Red Sox pitcher since Pedro Martinez won nine in a row in 1999. From August 7 on, Kelly went 7-0 and his 2.35 ERA (12 ER/46.0 IP) placed fourth in the American League (min. 30.0 IP).
Kelly has a team-best 14-8 (.636) record in 35 starts for the Red Sox (min. 10 decisions) since being acquired from the St. Louis Cardinals on July 31, 2014. In 103 career major league outings (73 starts) between St. Louis (2012-14) and Boston (2014-15), the California native is 31-22 with a 3.82 ERA (196 ER/461.2 IP) and 330 strikeouts.
With today's agreement, left-handed pitcher Robbie Ross Jr. and right-handed pitcher Junichi Tazawa are the only remaining unsigned Red Sox players eligible for salary arbitration.