Buchholz, 27, is tied for fourth in the American League with a .800 winning percentage (8-2) over his 14 starts with the Red Sox this year, while posting a 5.53 ERA (53 ER/86.1 IP) and 58 strikeouts. He is 5-1 with a 3.35 ERA (20 ER/53.2 IP) over his last eight starts, allowing three earned runs or less in six of those outings. Selected by the Red Sox in the supplemental round of the 2005 First-Year Player Draft, Buchholz owns a career 43-26 record with a 3.95 ERA (234 ER/533.1 IP) and 400 strikeouts in 92 Major League games (90 starts) with Boston since 2007.
Cook, 33, was placed on the disabled list on May 6 due to a left knee laceration that he suffered during his start against the Orioles a day earlier, his first start with Boston. The right-hander, who was selected to the Red Sox active roster on May 3, has also gone 3-0 with a 2.41 ERA (10 ER/37.1 IP) in six starts with Triple-A Pawtucket this year, including five to begin the season and a rehab start on June 18. Signed by the Red Sox as a minor league free agent in January, Cook owns a 72-69 career record with a 4.56 ERA (666 ER/1,315.0 IP) in 239 Major League appearances, including 207 starts, with the Rockies (2002-11) and Red Sox (2012). He was selected as a National League All-Star with Colorado in 2008 and ranks third among active Major Leaguers with at least 1,000.0 innings pitched with a 2.63 ground ball/fly ball ratio.