Ex-Red Sox Marcelo Mayer faces another injury setback

New team, same problem.

Former Red Sox shortstop Marcelo Mayer is dealing with right foot soreness with his new team, the San Francisco Giants.

The foot issue apparently stemmed from his time in Boston prior to being dealt on trade deadline day earlier this month. Giants manager Tony Vitello said Mayer “aggravated” the pre-existing ailment during his rehab assignment with the Triple-A Sacramento River Cats.

“He just aggravated it a little bit from being back out there every day,” Vitello said on Friday at Fenway (via NBC Sports Bay Area’s Alex Pavlovic). “He’s just going to take the weekend off and then kind of reassess things later.”

Mayer, 23, was traded from Boston to the Bay Area in exchange for left-handed relief pitcher Erik Miller. At the time, Mayer had been experiencing a stress reaction in his forearm. That injury has since cleared up, but his foot soreness prevented him from making his San Francisco debut back in Boston this weekend.

The Giants had hoped Mayer would have been able to join the big-league club for the series. 

Mayer played in four rehab games from Aug. 13-18 and seemed to be on the up and up. He averaged .353 with one home run in his first game; he recorded at least one hit in all of his appearances.

Defensively, Mayer played three games at second base and one at third. With the Red Sox in 2026, he played 45 games at 2B and 24 at SS, the latter being his natural position.

The former No. 4 overall draft pick in 2021 by Boston had struggled with the Red Sox before being dealt this season. In 70 games, Mayer batted .220 with a measly .594 OPS, three home runs, and 22 RBI. He struck out 44 times and walked on 16 occasions.

Mayer is no stranger to injuries, though his latest seems to be a minor affliction. He underwent season-ending surgery on his right wrist during his rookie campaign last August. He had made his MLB debut on May 24.

In 2024, Mayer suffered another season-ending ailment in August — that year, it was a lumbar strain. He played in 77 games for the Double-A Portland Seadogs.

2023 was a similar story. Left shoulder inflammation cut his season short in September, holding him to 78 games played between High-A and Double-A.

2026 has been more of the same. Mayer hasn’t played in a big-league game since July 23 and has yet to make his San Francisco debut.

Perhaps the change of scenery — one that’s closer to his hometown of Chula Vista, California — will be good for him once he recovers.

Kaley Brown

Sports producer

Kaley Brown is a sports producer for Boston.com, where she covers the Bruins, Celtics, Patriots, and Red Sox.