The Red Sox are acquiring infielder Caleb Durbin from the Brewers, reports Jeff Passan of ESPN. Milwaukee receives a three-player package including lefties Kyle Harrison and Shane Drohan as well as infielder David Hamilton, Passan adds. Boston is also picking up infielder Andruw Monasterio, catcher/infielder Anthony Seigler and a Competitive Balance Round B pick, per Will Sammon of The Athletic.
Durbin is a notable pickup for the Boston infield and should be penciled in for everyday at-bats — presumably at third base, though he can also handle second base if the Red Sox prefer Marcelo Mayer at the hot corner from a defensive standpoint. The 25-year-old Durbin (26 in a couple weeks) finished third in National League Rookie of the Year voting in 2025 after he batted .256/.334/.387 with 11 home runs, 25 doubles, 18 steals (24 attempts), a 5.9% walk rate and a tiny 9.9% strikeout rate. He turned in above-average marks for his glovework at third in the estimation of both Defensive Runs Saved (5) and Outs Above Average (2).
He’s not the big middle-of-the-order presence many Sox fans have coveted, but Durbin is an affordable, controllable and versatile defender who’ll further the Red Sox’ pivot toward run prevention and help to lower a team strikeout rate that was 10th-highest in the sport last year at 22.9%. He’s a right-handed hitter whose pull percentage (43.3%) is a bit higher than league average (40.6%), which should play well with the Green Monster at Fenway Park. Durbin comes to the Red Sox with five full seasons of club control and two minor league option years remaining (not that there’ll be any thought of optioning him to the minors anytime soon after last year’s strong performance).
If Durbin is ticketed for the hot corner, that’ll leave second base to a combination of the left-handed-hitting Mayer and righty-swinging Romy Gonzalez. Recently signed utilityman Isiah Kiner-Falefa can back up both those positions as well as shortstop.
The 28-year-old Monasterio could also factor in at either second or third base, although like Gonzalez and Kiner-Falefa, he’s a right-handed hitter. As is the case with Gonzalez, Monasterio also carries notable platoon splits. He’s a career .255/.352/.375 batter against lefties but a .246/.303/.338 hitter against fellow righties. He’s coming off a career-best showing in the majors — albeit in a limited sample of 135 plate appearances — having slashed .270/.319/.437 (111 wRC+) with four homers. He’s controllable for another four seasons and won’t be arbitration-eligible until at least next offseason (possibly later, depending on how much time he spends in the minors this year).
Monasterio also has nearly 3500 professional innings at shortstop under his belt, so he gives Boston another backup option to oft-injured Trevor Story at shortstop (alongside Kiner-Falefa). He also has a full slate of three minor league option years remaining, so there’s no guarantee he’ll open the season on Boston’s major league roster. He’ll have the opportunity to win a role in camp, but barring injury and/or trade, Boston’s bench seems likely to include Gonzalez, Kiner-Falefa, catcher Connor Wong and outfielder/designated hitter Masataka Yoshida.
All of that assumes that Mayer makes the Opening Day roster, but it’s possible that the former No. 4 overall pick could open the season in Triple-A Worcester, too. Mayer’s .228/.272/.402 slash was well below league-average in 2025, but he only turned 23 in December and has an impressive minor league track record. That includes a .271/.347/.471 showing in Triple-A last year. He’ll have every opportunity to win a starting job in camp with the Red Sox, but late additions of Durbin and Kiner-Falefa lessen the team’s reliance on the still largely untested top prospect.
Boston also picks up the 26-year-old Seigler, who’ll provide some depth in the upper minors and could be a frequently used bench piece over the course of the coming season. He’s batted just .194/.292/.210 in an insignificant sample of 73 major league plate appearances, but Seigler hit .285/.414/.478 with eight homers, 16 doubles, four triples, 23 steals (27 attempts), a 16.9% walk rate and a 19.2% strikeout rate in 307 Triple-A plate appearances this past season. He’s been used as an infielder (second base, specifically) far more frequently than a catcher in recent seasons due to troubles controlling the run game and a susceptibility to passed balls.
Even if he’s rarely deployed behind the plate, Seigler is at the very least an interesting third catcher option who also is comfortable at second base and third base. He has two minor league option years remaining and doesn’t even have a full season of major league service, making him controllable for at least the next six full seasons.
More to come.

