Lingering on the free agent market, however, is Bo Bichette, who after Alex Bregman’s agreement with the Cubs stands as the best clean fit for the Sox’ roster and needs. A shortstop by trade, Bichette played second for the Blue Jays upon returning from injury for the World Series. It almost certainly would require a mega-deal to land him — perhaps the largest contract ever given by the Red Sox to a free agent — but he would provide stability and production for a position group that needs it.

Get Starting Point

A guide through the most important stories of the morning, delivered Monday through Friday.

“Obviously, the infield has got some solidifying to do,” shortstop Trevor Story said Saturday afternoon, hours before Bregman joined the Cubs for five years and $175 million. “We don’t know where exactly it’s going to be.”

Either way, Mayer is positioned as a significant piece of the Sox’ 2026 plans, whether it be at second or third.

The offseason started with his bosses challenging him to put on muscle and get stronger; he now is at 218 pounds, up from 208 at the end of last season and “by far the heaviest I’ve ever weighed in my life,” he said. More recently, the Mayer talk has centered around his chances of serving as a true everyday player, not the platoon bat — sitting against most lefthanded starters — he was as a rookie.

“We’ve got to get him [at-bats] against lefties,” manager Alex Cora said of spring training plans.

Naturally a shortstop, he saw time at second and third in the majors in 2025 — and looked smooth at both spots.

Mayer, for his part, is looking forward to clarity and consistency about his defensive home.

“It’s not easy going into an offseason, kind of getting reps at every position,” he said Saturday. “I believe that every position requires different traits, different skills, different angles that you need to master. Obviously, I’m doing everything I can, taking reps at third and at second base, and I feel really good at both. So wherever they need me is where I’m going to play it, and I’m going to do my best.

“Playing third base is completely different than playing second base. So they each require a unique skill. Second base, you’re doing everything backwards [compared to being at shortstop]. Third base, you’re pretty much playing shortstop with less range, kind of quicker reflexes. There are just different skills that you need to hone in on to be great at that position.”

Romy Gonzalez (right) made 32 starts at second base last season for the Red Sox.Matthew J. Lee/Globe Staff

Behind Mayer is Gonzalez, who crushed lefthanders (.331/.378/.600) more than ever last year. He figures to get plenty of action against them again, whatever position that is at any given day. Last year he manned first base (41 starts), second (32), DH (two), and third (one). Cora mentioned Saturday that the Red Sox would “probably expand his role defensively, get him back to playing the outfield a little bit.”

Utilitymen David Hamilton, Nick Sogard, and Tristan Gray also are options on the 40-man roster. Kristian Campbell’s defensive focus lately is in the outfield, but he led the team with 54 starts at second last year. Ceddanne Rafaela, fresh off winning the AL Gold Glove for center field, will “probably not” play second this year, Cora said.

Highlighting the pipeline potentials is shortstop Franklin Arias, ranked by Baseball America as the Sox’ No. 2 prospect (behind Payton Tolle). He has dabbled at second in the minors. After finishing last season with Double A Portland, the 20-year-old was highly regarded enough by the front office (and close enough to the majors) to be included in their rookie development program, which is designed to help prospects assimilate to life in the majors.

Mikey Romero, a first-round draft pick in 2022, is also participating in the program, which runs through part of this week. He finished last year with Triple A Worcester, has moved around the infield, and is still only 22.

SECOND BASEMEN

Primary 2025 second basemen: Kristian Campbell, David Hamilton, Romy Gonzalez, Ceddanne Rafaela, Nick Sogard, Marcelo Mayer.

Projected 2026 second basemen: Mayer, Gonzalez.

Major league depth: Hamilton, Sogard, Tristan Gray, Campbell.

Prospects to watch: Franklin Arias, Mikey Romero.

Tim Healey can be reached at timothy.healey@globe.com. Follow him @timbhealey.