LaMarre, who will wear number 65, begins his first stint with Boston since signing with the Red Sox as a minor league free agent on December 14, 2015. In 44 games with Pawtucket this season, the 27-year-old has hit .313 (50-for-160) with eight doubles, six home runs, 19 RBI, 24 runs scored, and 11 stolen bases. The right-handed hitting outfielder made his major league debut with the Cincinnati Reds in 2015, making five starts and appearing defensively at center field (13 games), left field (two games), and right field (one game). A second-round selection by Cincinnati in the 2010 June Draft, LaMarre has played in 604 minor league games, totaling 99 doubles, 11 triples, 42 home runs, 193 RBI, 150 stolen bases, and 69 outfield assists while hitting .265 (575-for-2,168) with a .343 on-base percentage.
Marrero, who will wear number 16, is beginning his first major league stint of the season. The 25-year-old infielder has made 58 starts for the PawSox this year at shortstop (54 games), second base (two games), and third base (two games), hitting .216 (49-for-227) with nine doubles, one triple, and 17 RBI. Selected by the Red Sox as the 24th overall pick of the 2012 June Draft, Marrero made his major league debut in 2015, playing 25 games (12 starts) over three stints with Boston and batting .226 (12-for-53) with one home run, eight runs scored, and two stolen bases. In 446 career minor league games, the Miami native has hit .252 (430-for-1,706) with 86 doubles, 16 home runs, 157 RBI, and 84 stolen bases.
Castillo, 28, has made two starts and appeared in nine games over three stints with the Red Sox this season, going 2-for-8 with a double and four runs scored. He has also played in 38 International League games, posting a .245 average (36-for-147) with eight doubles, one home run, 13 RBI, and three stolen bases while appearing in center field (25 games), left field (eight games), and right field (six games). Signed by the Red Sox as an international free agent on August 23, 2014, the Cuban native has played in 99 major league games over the last three seasons, batting .262 (83-for-317) with 45 runs scored, 12 doubles, two triples, seven home runs, 35 RBI, and seven stolen bases.
Elias, 27, made his first start as a member of the Red Sox last night against the Mariners, suffering the loss after surrendering seven runs on seven hits in 4.0 innings. Acquired by Boston from Seattle this past December, the Cuban native has gone 15-21 with a 4.20 ERA (133 ER/284.2 IP) and 243 strikeouts in 53 games (50 starts) for the Mariners (2014-15) and Red Sox (2016). He is 4-3 with a 3.54 ERA (24 ER/61.0 IP) in 10 appearances (nine starts) with the PawSox this season, including 4-0 with a 2.00 ERA (8 ER/36.0 IP) and 40 strikeouts in his last five outings. The left-hander surrendered only one run in a complete-game effort on June 5 at Norfolk and threw 7.0 shutout innings on June 10 against Louisville.