With Alex Bregman’s departure over the offseason, Marcelo Mayer almost immediately assumed the position of Boston’s third baseman of the future and the present. But after trading for Caleb Durbin — who played 131 games at third base for the Brewers last year — last week, the Red Sox have become a bit jammed in the infield.
Granted, this is a much better problem to have than the absolute black hole that existed at second base last year, but it’s still something that will have to be addressed — and should be addressed quickly as the team looks to make up for Bregman’s All-Star level 2025 production through an amalgamation of pieces rather than a clear replacement.
Mayer’s rookie campaign last season consisted of fewer than 150 plate appearances and left something to be desired, especially with Roman Anthony’s meteoric rise as the closest point of comparison. Specifically, his patience at the plate will have to improve in 2026, and hopefully it will after an extended offseason following his wrist surgery toward the end of August. But on the defensive end, he proved to be nearly everything he was advertised to be, which is really saying something when you have Trevor Story and Bregman closest to you in the field.
Although he came up as a shortstop, Mayer has been projected to have the arm strength of a third baseman, and showed above-average range during his time at third base in the majors last year. This, along with the fact that Story has taken on a much bigger role for this team over the past year and Mayer didn’t start a single game at shortstop, shows Boston’s confidence in his ability to shift defensively to accommodate the roster’s current makeup.
On the other side of the coin, newest Red Sox Caleb Durbin advanced through the minor leagues as a much more versatile piece, splitting time between third, shortstop, and second while spending 18 games in the outfield in Scranton Wilkes-Barre in 2024 (for what reason, I do not know). But once he made his major league debut with the Brewers last year, he spent 13 games — and only started three — away from the hot corner. It was clear, at least in Milwaukee, that he was a designated third baseman, so how does that change with his move to Boston?
While Mayer and Durbin possess similarly graded “plus” arms, their defensive utility diverges sharply when you look at the ground they cover.
Last season, Mayer posted 3 OAA, albeit in a limited sample size, compared to Durbin’s 0 across a full season of action. This demonstrates the kind of lateral abilities that Mayer possesses that Durbin hasn’t shown yet, which overall makes him a better candidate to fill the hole at second than Durbin or other miscellaneous parts, as the Red Sox have seemingly forgotten about the Kristian Campbell Second Base Experience early in the spring.
Alex Cora has said he’s ready to work out this positional problem both in the spring and beyond, but he had the same assignment last year, and I can’t say he exactly aced it. A large part of this shortfall is definitely related to the lack of offensive production from the candidates at second base, but there’s not exactly a big degree of difference in that when it comes to this year’s choices, though Durbin has at least shown some relative consistency during his time in the majors.
The problem still remains that neither Durbin nor Mayer makes up for the offensive prowess that Boston should have added this offseason, and both will have to step up their offensive production this year (especially Mayer), but with the team’s makeup right now, it appears obvious that they will both be mainstays in the infield.