Boston Red Sox Position Analysis: Third Base

Entering the 2025 season, the Boston Red Sox made waves with a regime change at third base for the first time since 2017. Following their first postseason appearance since 2021, Boston will once again turn to a new face at the hot corner in 2026, this time in the form of Caleb Durbin.

Despite having Rafael Devers as the primary third baseman in 2025, Boston made a clubhouse-altering signing late in the offseason, bringing in two-time World Series Champion and former Gold Glove-winner Alex Bregman. While Bregman provided the Sox with offensive stability at third, as well as strong defense, the infield was never a puzzle the team was able to solve. A year later, both Devers and Bregman are with new teams, and the hot corner will look completely different.

Red Sox Third Baseman At A Glance

Starter: Caleb Durbin

Backup: Isaiah Kiner-Falefa

Depth: Marcelo Mayer, Andruw Monasterio

The Good

In January, Bregman signed a five-year, $175 million deal with the Chicago Cubs, leaving a gaping hole on the left side of Boston’s infield. Following Bregman’s departure, second-year infielder Marcelo Mayer seemed to be the top candidate for the job. Mayer took over the hot corner from late May to early July during Bregman’s stint on the injured list, providing above-average defense. However, recent trades by Boston have moved the former top prospect to second base for 2026.

With said trades, the Red Sox have put together a young core at the hot corner, including stability for the future under rookie contracts. Boston acquired Durbin and Monasterio from the Brewers in February in exchange for pitchers Kyle Harrison, Shane Drohan and infielder David Hamilton. The catch? Everyone that Boston acquired in the Devers trade is no longer on the roster. Perhaps a small price to pay for long-term stability? While the Devers trade may hurt, and parting ways with everyone they got in return stings, Boston has a lot to look forward to with the acquisition of Durbin.

Following the departure of Bregman, the Red Sox had three cornerstones they wanted to solidify at third base: youth, defense, and power. While Durbin is not the biggest home run threat, the 26-year-old has strong defensive upside and is entering his second full season at the big-league level. Durbin posted an impressive 2.8 WAR across 136 games in just his rookie season, including a stout .979 fielding percentage. He also hit .256 with 11 home runs and drove in 53 runs. Bregman sported a 3.5 WAR in 2025, but played in 22 less games. With Devers at third in 2024, the slugger posted a 3.7 WAR in 137 games, a slight increase, but with poor defensive play.
Durbin may not be a star, but he’s a high-floor replacement for the two most recent faces of the franchise.

The Bad

One of the biggest questions surrounding the team the last two seasons has been defensive efficiency. The Red Sox led the entire league in errors in 2025 with 116, six more than the next team in the Rockies. In 2024, Boston committed 117 errors, which was second most in the league. With the addition of Durbin, what will that number look like in 2026?

With Durbin being confirmed as the Opening Day starter at third base, there’s also questions about Mayer’s future. He played the majority of his 44 games in 2025 at the hot corner, but unfortunately for him, his rookie season ended in late July, as he underwent wrist surgery in August. In his shortened season, he hit just .228 with four home runs and 10 RBI. Mayer is likely to find most of his playing time at second, but will be a viable backup for Durbin at third.

Neither is an offensive savant, and Kiner-Falefa would be lucky to hit somewhere around league average. Have the Red Sox traded too much stick for the improved gloves?

The Bottom Line

Boston’s infield defense has significantly improved with the offseason additions of Durbin and Willson Contreras at first, plus whatever Mayer provides at the keystone. After years of fielding superstars like Bregman and Devers at the hot corner, it’ll be difficult to accept someone who does the little things well but doesn’t carry the team, but Durbin is a foundationally solid, cheap piece to build the rest of the infield group around. He should have a nice season playing alongside Trevor Story on the left side of the infield.