The Boston Red Sox put right-handed reliever Justin Slaten on the 15-day injured list due to shoulder inflammation.
It was one of several roster moves the Red Sox made Sunday morning, which included replacing Slaten on the roster with right-hander Luis Guerrero, who was called up from Triple-A Worcester.
The Red Sox also selected the contract of utility player Nate Eaton and optioned infielder Nick Sogard to Triple-A, designating catcher Blake Sabol for assignment to clear roster space.
Slaten, 27, has been a key piece of Boston's relief staff this spring, despite his 1-4 record. He has appeared in 24 games with a 3.47 ERA over 23⅓ innings.
A third-round pick of the Texas Rangers in 2019, Slaten is in his second season with the Red Sox. A year ago, he went 6-2 with a 2.93 ERA and 58 strikeouts over 44 appearances.
He's been less dominant in 2025 and has cited fatigue as a reason for the dip.
Guerrero, 24, has been stellar in limited major league action over two seasons, posting a sparkling 0.59 ERA over 15⅓ innings (13 appearances).
Overall, Guerrero is 14-12 with a 3.11 ERA in 133 minor league appearances.
Eaton, who plays the outfield and third base, was a 21st-round 2018 draft pick of the Royals. He has 159 major league at-bats, hitting .201. The 28-year-old last appeared in the majors for Kansas City in 2023.
Sogard, 27, hit .245 for Boston this year in 14 games (49 at-bats).
Sabol, 27, has an even smaller sample size this year than Sogard (eight games, 16 at-bats), but has had limited success, batting .125.