Marcelo Mayer fills infield void in major league debut

The Red Sox suddenly had a third base problem after a recent injury to Alex Bregman, but it created an opportunity to bring up their top infield prospect in Marcelo Mayer.

Primarily a shortstop and still the likely long-term answer at that position, Mayer had still played four games at third base for Triple-A Worcester so far in the 2025 season. He should be enough of a natural athlete to play third in a pinch, and a pinch is the gentle way of describing the Red Sox' injury situation at the hot corner right now.

Mayer filed the void admirably in his major-league debut on Saturday night, as the Red Sox played the back half of a double-header against the Orioles. Mayer came up empty at the plate, as he went 0-for-4 and struck out three times, but he has more than enough offensive upside to inspire confidence that he'll find a way to adjust to major-league pitching.

Where Mayer played a much bigger role in the game was in the field. He started at third base and made a putout against the Orioles' Ramon Urias on his first defensive opportunity as a major leaguer. He made another putout in the seventh inning when he finished off a missile from right fielder Rob Refsnyder, nabbing Heston Kjerstad at third.

Mayer got to move to shortstop after Wilyer Abreu pinch hit for Trevor Story, moving Nick Sogard over to third. Mayer later moved back to third, after Billy Hamilton pinch ran for Sogard.

The 22-year-old got a standing ovation from hopeful Red Sox fans at Fenway Park as he stepped in for his first career at-bat.

"It was awesome, I've never experienced anything like that in my life," Mayer said. "I just finished texting with friends and family about that moment. Definitely something I'll remember for the rest of my life."

^{Marcelo Mayer}

Though it would've been a more memorable debut had Mayer been able to do damage at the plate, an adjustment period and learning curve should be expected for a young prospect jumping to the majors. It's possible that Boston gives him time to figure it out, as evidenced by the fact that he's right back in the starting lineup at third base in Sunday's series finale.

The question is what happens with Mayer once Bregman is able to return, but he should stay up for the foreseeable future as Bregman hits the injured list. Mayer has already proven that he can fill in defensively, so we'll see if he can get rolling with his bat.