How New Lefty Reliever Impacts Red Sox Bullpen Construction

The Boston Red Sox made their first acquisition of the offseason Thursday when they signed reliever Justin Wilson to a major-league deal.

The former Cincinnati Reds reliever struggled in 2024, though his veteran status may appeal to the Red Sox if he can bounce back in what will be his age-37 season.

2024: 60 G, 1-5, 5.59 ERA, 46 2/3 IP, 51 K, 13 BB, 4.73 FIP, 9.8 K/9
Career: 587 G, 34-29, 3.61 ERA, 513 2/3 IP, 561 K, 223 BB, 3.57 FIP, 9.8 K/9

Left-handed relief was a general struggle for Alex Cora’s team last year, failing to find any sort of consistency and getting further exposed in a second-half regression from the Red Sox bullpen as a whole.

Here’s what the Red Sox got from their left-handed relievers in 2024 (with more than 10 appearances):

Brennan Bernardino: 57 G, 4-3, 4.06 ERA, 51 IP, 56 K, 22 BB, 4.15 FIP, 9.9 K/9
Cam Booser: 43 G, 2-3, 3.38 ERA, 42 2/3 IP, 43 K, 16 BB, 3.80 FIP, 9.1 K/9
Bailey Horn: 18 G, 1-1, 6.50 ERA, 18 IP, 13 K, 10 BB, 7.00 FIP, 6.5 K/9
Joely Rodriguez: 14 G, 0-1, 5.93 ERA, 13 2/3 IP, 12 K, 2 BB, 4.92 FIP, 7.9 K/9

Wilson, who joins his seventh MLB team, has upside and experience. He likely won’t be a leverage arm for Boston, but he can attempt to settle the storm among southpaws. Zach Penrod looked sharp in September and posted a 2.25 ERA in seven outings. He could pitch his way to a spot in spring training, though the Red Sox should maintain aggression in searching for impact relievers this winter.

Enter Tanner Scott?