Prior to tonight's game against the Seattle Mariners, Boston Red Sox right-handed pitcher Craig Kimbrel was returned from his injury rehab assignment with Triple-A Pawtucket and activated from the 15-day disabled list. To make room on the 25-man roster, the club optioned right-handed pitcher Joe Kelly to Pawtucket.
President of Baseball Operations David Dombrowski made the announcement. 
Kimbrel, 28, was placed on the disabled list with a left knee medial meniscus tear on July 9. He underwent a successful left knee arthroscopy and partial medial meniscectomy on July 11, with Head Team Orthopedist Dr. Peter Asnis performing the surgery at Massachusetts General Hospital. The right-hander made his lone rehab appearance with the PawSox on Saturday, hitting a batter and surrendering one hit in 0.1 innings. Named to this year's American League All-Star team as a manager's selection, Kimbrel has gone 1-3 with a 3.55 ERA (13 ER/33.0 IP) and 50 strikeouts in 34 appearances, 28 of which have been scoreless. In his first year with the Red Sox, Kimbrel ranks fourth among AL relievers in strikeouts per nine innings (13.64) and eighth in opponent batting average (.178) and has converted 17 of his 19 save opportunities. Over his big league career, the Huntsville, AL native has gone 20-15 with 242 saves, a 1.79 ERA (76 ER/381.1 IP), and 613 strikeouts in 389 games for the Atlanta Braves (2010-14), San Diego Padres (2015), and Red Sox (2016).
Kelly, 28, is 2-0 with a 7.62 ERA (22 ER/26.0 IP) and 28 strikeouts in nine appearances (six starts) for Boston this season. He pitched only out of the bullpen in his latest major league stint, allowing one run in 3.2 innings over three outings in his first relief appearances as a member of the Red Sox. Selected by the Cardinals in the third round of the 2009 June Draft, the California native has made 112 appearances (79 starts) between Boston and St. Louis, combining to go 33-22 with a 4.02 ERA (218 ER/487.2 IP). He has posted a 3.20 ERA (20 ER/56.1 IP) in 33 major league relief appearances and is 31-19 with a 4.13 ERA (198 ER/431.1 IP) as a starter. Kelly pitched only as a reliever in his latest stint with the PawSox, allowing zero runs and five hits in 5.0 innings while recording nine strikeouts against one walk over four appearances.