Velázquez, 28, is 4-1 with a 1.29 ERA (7 ER/49.0 IP) and a .189 opponent batting average in nine starts with the PawSox this season. He has struck out 35 batters and walked eight, allowing 32 hits and only one home run. A native of Sonora, Mexico, has made five scoreless starts of at least 5.0 innings, having not allowed a run in his last 16.0 innings pitched. The Red Sox purchased his contract from the Piratas de Campeche of the Mexican League on February 18, 2017, and in his lone major league start on May 18 at Oakland he allowed six earned runs over five innings and suffered the loss. In seven seasons with Campeche (2010-15) and Monclova (2016), the right-hander went 43-29 with a 3.76 ERA (287 ER/687.1 IP) in 136 appearances (120 starts).
Marrero, 26, has hit .157 (13-for-83) with three doubles and three home runs in 33 games over two stints with Boston this season. He has made 23 starts-20 at third base and three at second base-for the major league club, with the Red Sox going 15-8 in those games. He has also played 19 games with the PawSox this season, going 12-for-71 (.169) with four runs, three doubles, and four RBI. Since making his big league debut for Boston in 2015, the Miami native has gone 26-for-148 (.176) in 71 major league games. Ranked by Baseball America as the best defensive infielder in the Red Sox organization, Marrero has a .243 batting average (465-for-1,913) with 91 doubles, seven triples, 17 home runs, 169 RBI, and 89 stolen bases in 503 career minor league games.