Fifth in a series about the Red Sox roster entering the 2026 season. Read more: Part 1: Starting pitching | Part 2: Bullpen | Part 3: First base | Part 4: Second base
The first full-squad workout of spring training is in four weeks, and the only clarity the Red Sox have about third base is that Alex Bregman won’t be returning.
After an All-Star season with the Sox, Bregman signed with the Cubs for five years and $175 million. That left a hole in the lineup that could be filled in several ways.
The most direct path would be to sign free agent Eugenio Suárez, who hit 49 home runs and drove in a career-best 118 runs for the Diamondbacks and Mariners last season.
The 34-year-old righthanded-hitting slugger has struck out in nearly 34 percent of his at-bats since 2019, and is coming off of a poor defensive season. But he does provide power and has a 1.277 OPS in 10 career games at Fenway Park.
The best in-house solution is 23-year-old former first-round pick Marcelo Mayer, who started 28 games at third base while Bregman was on the injured list with a quadriceps strain. He handled the position well defensively but had only a .674 OPS over 136 plate appearances.
A tear in his right wrist ended Mayer’s season on July 23, and he had season-ending surgery on Aug. 20. Mayer has since recovered and will be ready for spring training, but he has yet to play more then 91 games in a season since being drafted in 2021 because of injuries.
“I feel good. I’m pretty much doing full baseball activities like a normal ramp-up. I feel like I’m in a good spot,” Mayer said this month.
Mayer also gained 10 pounds, something the team requested. His added strength should help at the plate.
“My goal right now is just to get to spring training in the best shape I can and go out there and perform,” Mayer said. “You’re in the big leagues now. For me, the real work starts now. I’ve definitely gotten after it this offseason. You learn from experience what you need to work on.”
The Sox also have an opening at second base, another position where Mayer would fit if he stays healthy.
Nate Eaton (10 starts), Nick Sogard (three), and Romy Gonzalez (one) also saw time at third base. None profile as everyday players there, but are good enough to pick up days when needed.
Vinny Capra, who was signed to a minor league contract in November, has 67 games of major league experience, 30 of them at third base. He’ll be in major league spring training.
The Sox also have Mikey Romero, their first-round pick in 2022. He has started 45 games at third base in the minors, 25 of them with Triple A Worcester last season. For now, the Sox see him as a depth option, not a candidate to become a starter.
There’s also the possibility of a trade. The Sox have outfield and pitching depth they could use to acquire a third baseman to replace Bregman or a second baseman who would allow Mayer to focus on third base.
Second baseman Brendan Donovan (Cardinals) is on the market, with the Mariners a possibility as St. Louis works to shed even more payroll.
Infielders Brett Baty (Mets), Nico Hoerner (Cubs), and Isaac Paredes (Astros) aren’t necessarily available, but that could change. As spring training approaches, trades tend to become less likely.
THIRD BASEMEN
Primary 2025 third baseman: Alex Bregman.
Projected 2026 third baseman: Marcelo Mayer.
Major league depth: Nate Eaton, Romy Gonzalez, Nick Sogard, Vinny Capra.
Prospect to watch: Mikey Romero.
Peter Abraham can be reached at peter.abraham@globe.com. Follow him on Bluesky at peteabeglobe.bsky.social.