Executive Vice President/General Manager Ben Cherington made the announcement.
Barnes, 25, will be making his first career major league start tonight. In 21 relief appearances over three stints with the Red Sox this season, he is 3-2 with a 5.64 ERA (14 ER/22.1 IP) and 22 strikeouts. With the PawSox this year, the Connecticut native went 1-1 with a 4.17 ERA (17 ER), striking out 39 batters in 36.2 innings. Barnes, who made his big league debut with five relief outings for the Red Sox last season, is 3-2 with a 5.17 ERA (18 ER/31.1 IP) in his major league career with 30 strikeouts and only 10 walks. Signed by the Red Sox as a first-round selection in the 2011 June Draft, he is 22-25 with a 3.69 ERA (163 ER) and 417 strikeouts in 397.1 innings pitched over 89 career minor league outings (77 starts) from 2012-15.
Hembree, 26, has appeared in four games with the Red Sox over three previous major league stints this season, with no record, an 8.53 ERA (6 ER/6.1 IP), and three strikeouts. His last big league stint included time on the disabled list with right shoulder inflammation from June 15-July 24, after which he was optioned back to Pawtucket. Overall with the PawSox this season, including rehab outings, the right-hander is 0-5 with eight saves and a 2.27 ERA (8 ER/31.2 IP) in 29 relief appearances. For his big league career, Hembree has no record, a 4.95 ERA (11 ER/20.0 IP), and 21 strikeouts in 17 games between the San Francisco Giants (2013) and Red Sox (2014-15). He was acquired by Boston along with left-handed pitcher Edwin Escobar via trade with the Giants in exchange for right-handed pitcher Jake Peavy and cash considerations on July 26, 2014.
Cook, 28, has made three relief appearances in two stints with Boston this season, allowing nine earned runs on 10 hits in 2.0 innings of work. Acquired from the Oakland Athletics on July 31 in exchange for a player to be named later or cash considerations, the right-hander has also made two relief appearances for Pawtucket, recording three strikeouts and retiring all seven batters faced. Cook has spent the majority of this season with Oakland's Triple-A Nashville affiliate, going 4-1 with eight saves, a 4.05 ERA (15 ER/33.1 IP), and 26 strikeouts in 30 relief outings. A member of the 2012 American League All-Star Team, he is 13-12 with 17 saves, a 3.30 ERA (75 ER/204.2 IP), and 210 strikeouts in 215 career major league outings, all in relief, between the Arizona Diamondbacks (2011), A's (2012-15), and Red Sox (2015). He was originally selected by Arizona in the 27th round of the 2008 June Draft.
Cecchini, 24, went 0-for-4 in two games with Boston in his first major league stint of the season this past weekend, making one appearance at first base and one as a designated hitter. The left-handed batter made his major league debut with 11 games for Boston over three major league stints in 2014, going 8-for-31 (.258) with three doubles, a homer, four RBI, and three walks. In 100 games with Pawtucket this season, he has hit .218 (79-for-362) with 14 doubles, six home runs, 25 RBI, and 35 walks, including a .284 (33-for-116) average in his last 32 games dating back to July 7. With the PawSox this season, he has seen time primarily in left field (57), as well as at third base (19 games) and first base (14 games). Selected by the Red Sox in the fourth round of the 2010 June Draft, the Louisiana native has hit .282 (505-for-1,792) with 118 doubles, 13 triples, 27 homers, 228 RBI, 105 stolen bases, and 251 walks over his five-year minor league career.