Barnes, 25, returns to the club for his third stint in the major leagues this season. The right-hander last appeared for Boston on June 13 against Toronto. Barnes has appeared in 15 games for the Red Sox this season going 2-2 with a 4.24 ERA (8 ER/17.0 IP) and 13 strikeouts. In nine outings for the PawSox this season, including three starts, he is 1-0 with a 4.42 ERA (9 ER/18.1 IP) and 23 strikeouts. A native of Connecticut, Barnes owns a 4.15 ERA (12 ER/26.0 IP) in 20 career big league games, all out of the bullpen. Signed by the Red Sox as a first-round selection in the 2011 June Draft, he is 22-24 with a 3.68 ERA (155 ER) and 401 strikeouts in 379.0 innings pitched over 82 career minor league outings (75 starts) from 2012-15.
Shaw, 25, has appeared in six games in three major league stints this season, going hitless in nine at-bats with one walk and a run scored. He has played in three games (one start) at third base and in two games (one start) at first base, also making one appearance in left field. In 58 contests for Pawtucket this season, he has hit .259 (57-for-220) with nine doubles, two triples, five home runs, 26 RBI, and 22 walks, appearing in games at third base (32 games), first base (22), and left field (3). Signed by the Red Sox as a ninth-round selection in the 2011 June Draft, Shaw has hit .262 (480-for-1,829) with 117 doubles, 11 triples, 69 home runs, and 276 RBI in 502 games over parts of five seasons in the minor leagues.