Getty Images

The Boston Red Sox made an interesting addition to their bullpen on Friday, and in the process made a notable subtraction from their 40-player roster. The Red Sox acquired righty Wyatt Mills from the Kansas City Royals in exchange for pitching prospect Jacob Wallace. To make room for Mills on the 40-player roster, the Red Sox designated first baseman Eric Hosmer for assignment.

Of course, you can be excused if you find the most worthwhile part of this transaction cluster to be Hosmer. He came over from the San Diego Padres last deadline as part of their reshuffling and appeared in 14 games for Boston while missing time because of back woes. Hosmer will now be traded or exposed to waivers in the coming days, with the latter eventually leading to his release.

It should be noted that the Red Sox are responsible for a trifling amount of the $39 million remaining on Hosmer's contract. As part of the terms of the trade, Boston will owe Hosmer the minimum in each of the three years left on his deal, resulting in a total cost of just over $2.2 million. 

Hosmer, 33, could draw some interest as a free agent. During the Pandemic Era, he's batted .271/.335/.407 (110 OPS+) with much of his damage coming against right-handed pitching. The Red Sox simply had no use for him, given the presence of youngsters Bobby Dalbec and Triston Casas.

Mills, soon to turn 28, has made 38 big-league appearances over the last two seasons as a member of the Seattle Mariners and Royals. (He was traded to Kansas City as part of June's Carlos Santana deal.) He's accumulated a 6.21 ERA (66 ERA+) and a 1.85 strikeout-to-walk ratio in those outings, undoubtedly poor marks, but there's reason to think he has some upside.

Part of Mills' promise revolves around his release point. He's a 6-foot-4 submariner who really gets down the mound, creating exceptional depth and an unusual angle for right-handed batters. That effect has been captured in his statistics. Although his numbers have been poor overall, he's held righties to a .239/.361/.321 slash line; lefties, conversely, have hit .365/.397/.596. 

It seems reasonable to think Mills, who has an option year remaining, could fill in as a right-handed specialist, at minimum. That was enough for the Red Sox to justify giving up Wallace, a 24-year-old who walked nearly a batter per inning last season in 47 appearances at Double-A. The Red Sox originally obtained Wallace from the Colorado Rockies as the return on outfielder Kevin Pillar in September 2020.