Matsuzaka, 31, began the season on the 15-day disabled list recovering from Tommy John Surgery that he underwent on June 10, 2011, and was transferred to the 60-day disabled list on May 22. He combined for a 3.65 ERA (15 ER/37.0 IP) and 30 strikeouts with an 0-3 record in eight minor league starts between two rehabilitation stints this year, including one start with High-A Salem and Double-A Portland and six with Triple-A Pawtucket. The right-hander was removed from rehab due to a right trapezius strain on May 19 and returned for his final three starts with the PawSox beginning May 26, allowing just two runs over 11.2 innings (1.54 ERA) with just six hits allowed in that three-game stretch. Matsuzaka made eight appearances (seven starts) for the Red Sox in 2011 through May 16 of that season, going 3-3 with a 5.30 ERA (22 ER/37.1 IP) and 26 strikeouts. Signed by Boston as a free agent on December 14, 2006, he has a career 49-30 record with a 4.25 ERA (294 ER/622.2 IP) and 568 strikeouts in 106 Major League games (105 starts).
Byrd has appeared in 34 games for the Red Sox this year since being acquired from the Cubs on April 21, including 26 starts in center field and one in right field. The 34-year-old has batted .270 (27-for-100) with two doubles, one home run, seven RBI, nine runs scored and two walks with Boston in 2012. Originally selected by Philadelphia in the 10th round of the 1999 First-Year Player Draft, the right-handed batter has hit at a .278 clip (1,067-for-3,835) with 217 doubles, 27 triples, 82 home runs and 445 RBI in 1,103 career games over parts of 11 Major League seasons with the Phillies (2002-05), Nationals (2005-06), Rangers (2007-09), Cubs (2010-12) and Red Sox (2012).
The 24-year-old Kalish began the season on the 60-day disabled list recovering from left shoulder surgery. He combined to hit .375 (12-for-32) with three doubles, three home runs, six RBI, eight runs scored, nine walks and two stolen bases in nine rehab games this season, including three contests each with Salem, Portland and Pawtucket. A left-handed batter, he has 53 games of Major League experience, all with the Red Sox in 2010, and has hit .282 (423-for-1,498) with 79 doubles, 11 triples, 43 home runs and 206 RBI in 400 career minor league games since being selected by Boston in the ninth round of the 2006 First-Year Player Draft.
Repko, 31, was placed on the 15-day disabled list on April 23 (retroactive to April 21) due to a left shoulder sprain. He has appeared in five games for the Red Sox this season, including four starts in center field, and also played four games with Pawtucket prior to his selection to Boston on April 15. Signed by the Red Sox as a minor league free agent in January, Repko has appeared in 360 Major League games over seven seasons with the Dodgers (2005-06, 2008-09), Twins (2010-11) and Red Sox (2012), batting .224 (157-for-700) with 29 doubles, four triples, 16 home runs, 67 RBI, 105 runs, 52 walks and 27 stolen bases.