The Boston Red Sox are promoting top infield prospect Marcelo Mayer on May 24, following third baseman Alex Bregman's injury a day prior. Mayer, the fourth overall pick in 2021, has 43 RBIs in 43 games for Class AAA Worcester this season. The 22-year-old was drafted as a shortstop and played almost exclusively there in his five minor-league seasons, but has gotten reps some at second and third in 2025. A left-handed hitter, Mayer is big for a shortstop at 6-foot-3 and has struggled at times against lefties in the minors (.674 OPS in 2024), but his power profiles well and has a strong arm that will be useful at any infield position. Boston's infield is something of a puzzle this year, with the winter addition of Bregman pushing Rafael Devers off the hot corner to designated hitter. Rookie Kristian Campbell began the season at second base and Trevor Story has been the shortstop, but the veteran has a .607 OPS through 49 games. First baseman Triston Casas suffered a season-ending injury earlier in May, and Deversdeclined the team's requestto give the position a shot – leading to Boston preparing Campbell to play first. Marcelo Mayer is headed to Boston ladies and gentlemen🥹pic.twitter.com/RtwcNXR733 — Natalie Noury (@NatalieNoury)May 24, 2025 With Campbell established in Boston and Mayer joining the group, next up in the pipeline for the Red Sox is outfielder Roman Anthony, currently ranked as baseball's No. 1 overall prospect by MLB.com. The 21-year-old is hitting .323 with a .968 OPS and should reach the majors this season. "About time," Anthony posted on Instagram as news of Mayer's promotion spread. "Go be you brother." Marcelo Mayer is hitting .271 with nine home runs and 43 RBIs in 43 games for Class AAA Worcester. In 2024, Mayer hit .307 with an .850 OPS at Class AA Portland. (Pre-2025 season rankings) Baseball America: No. 15 overall Major League Baseball: No. 12 Baseball Prospectus: No. 25 This article originally appeared on USA TODAY:Red Sox promote prospect Marcelo Mayer after Alex Bregman injury
