The Boston Red Sox's first offensive reinforcement came in the form of veteran catcher/first baseman Willson Contreras. The former St. Louis Cardinal — Boston's only return in its third deal with them since the 2025 trade deadline — will reportedly split his time between first base and designated hitter this coming season.
In Contreras' first season as a full-time first baseman, he logged six outs above average and 91st percentile range. There's room for improvement, of course, but after years of almost exclusively catching, the position change could come easily to him.
Contreras is a clear defensive upgrade over Triston Casas (-10 OAA and second-percentile range in 2023) and Pete Alonso (-9 OAA, second-percentile range last season), a Red Sox free agent target. He also gives Boston a solid foundation at first base, which it hasn't had in the past few seasons as Casas has dealt with severe injuries which has forced it to turn to inexperienced options such as Dominic Smith and Abraham Toro (subscription required).
This new defensive skill and stability could help the Red Sox drastically cut down on their errors this coming season. Boston clocked a staggering 116 errors, the most in MLB, the vast majority of them came in the infield. Much of them could be attributed to inexperience around the infield, particularly at first and second base, but trading for Contreras and reuniting with Alex Bregman could help the Red Sox drastically decrease that number (subscription required).
Willson Contreras and Alex Bregman would be a highly successful defensive corner infield duo for the Red Sox
Bregman (who went through an adjustment period this year and logged nine errors of his own) still has top tier range at third base and he could be an even more anchoring presence in a full healthy season. He logged three outs above average and 83rd-percentile range, undeniably an upgrade from Rafael Devers.
Re-signing Bregman could allow for an upgrade in the middle infield. Boston has already committed to Trevor Story as its shortstop for 2026, and although he had a rough defensive season, there were bound to be bumps in the road after he went three years without playing a full slate of games. Even a partial rebound from Story, who made 19 errors, will be a big boost to the defense.
Bregman at third base and Story at shortstop leaves second base open for Marcelo Mayer. His smooth defense is far better than Kristian Campbell's and his 26th-percentile arm strength plays much better on the first base side of the infield
Casas will still likely get some playing time at first base, since the Red Sox have announced that Contreras will also suit up as the DH sometimes, but not only will the latter's superior defense help lift the infield as a whole, Casas will spend less time on his feet and, in theory, reduce the risk of injury. But in order for the Red Sox to field their best possible defensive infield and stop the longstanding disaster that has cost them so many runs, a reunion with Bregman is a must.