With one infielder on his way out at the MLB trade deadline, the Giants reportedly are acquiring another.San Francisco has completed a trade for utility infielder and former top prospect Marcelo Mayer from the Boston Red Sox in exchange for relief pitcher Erik Miller and outfield prospect Carlos Gutierrez, the team announced Monday. ESPN’s Jeff Passan was first to report the news. The #SFGiants and Boston Red Sox completed a trade today with IF Marcelo Mayer joining the Giants in exchange for LHP Erik Miller and minor league OF Carlos Gutierrez.
— SFGiants (@SFGiants) August 3, 2026 The Red Sox selected Mayer with the No. 4 overall pick in the 2021 MLB Draft, and he was viewed by many as the draft’s top prospect as a five-tool player. He made his MLB debut at third base on May 24 during the 2025 campaign after Alex Bregman was injured, then underwent season-ending wrist surgery in August of that year.
During the 2026 MLB season, Mayer has appeared in 70 games with 59 starts, playing 45 games at second base and 24 at shortstop. He’s slashing .220/.282/.312 with three home runs and 22 RBI. After trading Luis Arraez to...