The Boston Red Sox’ 2026 season has been filled with disappointments. Marcelo Mayer, the organization’s former top prospect, is among them.
Mayer’s first full big-league season has been a struggle, particularly at the plate. The 23-year-old has produced a meager .594 OPS with three homers through 70 games.
Defensively, Mayer looked sharp at second base before taking over for the injured Trevor Story at shortstop. In 24 games at the position, he has looked rusty with -2 Defensive Runs Saved and two errors, including one on a routine ground ball that ultimately doomed Boston in Wednesday’s series finale vs. the Colorado Rockies.
Mayer’s woes are unfortunate, albeit predictable for a young player still acclimating to the majors. It’s what’s going on in his head, not just on the field, that has drawn criticism from some members of the Red Sox organization, according to MassLive.com’s Sean McAdam.
“To be sure, Mayer has his detractors within the organization,” McAdam wrote. “Some question his mental toughness and his tendency to withdraw during slumps. Others wonder if he couldn’t do a better job making himself more available through the day-to-day minor physical setbacks that inevitably occur.”
Mayer missed time earlier this month due to upper-body discomfort and was also held out of Boston’s starting lineups on Tuesday and Wednesday after fouling a ball off his foot. Coincidentally, just hours after McAdam’s report was published, Mayer was placed on the 10-day injured list with a forearm issue.
The note on Mayer’s mental toughness during slumps is noteworthy after his comments about his costly error in Colorado. The No. 4 pick took accountability, but was visibly upset with himself after the mishap.
“I couldn’t get the ball out of my glove,” he told reporters. “That can’t (expletive) happen. … Just a brutal error that cost us the game. To me, it’s the most routine ground ball I could possibly get. This game’s 100 percent on me.”
Mayer, Roman Anthony, and Kristian Campbell made up Boston’s exciting “Big Three” prospects heading into the 2025 season. Each of them has been disappointing for different reasons, with injuries plaguing Anthony and poor performance keeping Campbell down in Triple-A since last year’s demotion.
With a 33-46 record, this is likely a lost season for the Red Sox. Still, Mayer turning things around and finally showcasing his potential would go a long way toward inspiring some optimism in his and the organization’s futures.


