What Red Sox's Lineups Tell Us to Expect About Marcelo Mayer, Opening Day

The Boston Red Sox's infield is going to be fun to watch.

Jun 30, 2025; Boston, Massachusetts, USA; Boston Red Sox third baseman Marcelo Mayer (39) reacts after making an out during the eighth inning against the Cincinnati Reds at Fenway Park. Mandatory Credit: Bob DeChiara-Imagn Images | Bob DeChiara-Imagn Images

The Boston Red Sox haven't specifically announced what their infield is going to look like and likely won't until we get closer to Opening Day, but things are starting to get pretty clear.

The only two question marks for Boston in the field right now technically are second base and third base. Carlos Narváez is the club's starting catcher. Willson Contreras and Trevor Story are the starters at first base and shortstop. All four outfielders (Jarren Duran, Roman Anthony, Wilyer Abreu and Ceddanne Rafaela) are going to get plenty of time, including as designated hitter. Second base and third base have been the only positions seemingly not locked up.

Arguably, that has shifted simply by just looking at the club's lineups in Spring Training. Caleb Durbin has been at third base for the vast majority of his playing time. Also, Red Sox manager Alex Cora pretty much said that he is the team's third baseman.

Marcelo Mayer and Caleb Durbin will have big roles

Feb 27, 2026; North Port, Florida, USA; Boston Red Sox second baseman Marcelo Mayer (11) throws to first base in the second inning against the Atlanta Braves during spring training at CoolToday Park. Mandatory Credit: Jonathan Dyer-Imagn Images | Jonathan Dyer-Imagn Images

"Caleb, he’s playing third base again [Tuesday],” Cora said on March 10. “We’ll probably decide that next week. But I feel very comfortable with him at third base. ... Honestly, [the intrigue] is more for [reporters]. It’s kind of like, ‘What are we going to do? [It’s been] five [straight] days of playing third base. He played the whole season....It’s more for you guys than me."

When Marcelo Mayer has played, he has gotten the vast majority of his playing time at second base, including on Thursday as he batted third in the lineup. And, oh look, Durbin was at third base.

Taking on the Twins. pic.twitter.com/bQREOLGGCV

— Red Sox (@RedSox) March 12, 2026

Mayer was batting third and playing second base on Tuesday as well.

Sonny Gray on the mound in the Fort! pic.twitter.com/edCmt14DJF

— Red Sox (@RedSox) March 10, 2026

That was the case on Monday as well.

Crochet on the mound at Fenway South! pic.twitter.com/Pze2tBF4ra

— Red Sox (@RedSox) March 9, 2026

The list goes on. The Red Sox may not technically "announce" anything, because they really don't need to yet. But all of the signs are pointing towards Mayer being the club's second baseman in 2026 and Durbin being the club's third baseman. Again, there is no reason for an "announcement." The Red Sox don't need need to fully unveil the roster until we get closer to Opening Day. But the signs are there.