By in large, the Boston Red Sox's bullpen has been a strength of the team in 2025. They rank third by fWAR (2.7) in all of baseball and sport a 3.64 ERA and 3.48 FIP across over 222 innings of work. That production has been a collective effort, but the consistency that Justin Slaten has given them has played a massive role. Unfortunately, the latest injury news from the Red Sox is threatening that dominance.
While Aroldis Chapman gets all the attention as the team's primary closer, Slaten has quietly done great work this season. His strikeout rate leaves a lot to be desired, but he pounds the strike zone and just hasn't given up hard contact this season leading to mostly breezy appearances out of the bullpen.
Unfortunately, the Red Sox had to place Slaten on the injured list on Sunday with what was described as right shoulder inflammation in arguably the biggest test to Boston's relief depth so far.
Red Sox place Justin Slaten on the injured list amidst flurry of roster moves
Losing Slaten is a pretty big blow. So far, the description of his injury is just inflammation, but it seems more and more these days that this type of IL stint becomes lengthy more often than not. Given that Slaten is a power pitcher that relies on a high velocity fastball, any sort of shoulder issue is particularly problematic.
In his place, the Red Sox are bringing up Luis Guerrero. While his 4.43 ERA and questionable K:BB ratio in Triple-A are concerns, he did look pretty good in a short stint with Boston earlier this season, aside from the walk problems.
As for the other moves, they are pretty standard housekeeping moves. Blake Sabol has done next to nothing in limited action, and the Red Sox have Carlos Narvaez and Connor Wong to hold things down behind the plate. The Red Sox also swapped out utility man Nick Sogard, who had little in the way of offensive upside, for Nate Eaton, who has posted an .811 OPS so far down at Triple-A and who has similar defensive versatility.