Red Sox reliever Justin Slaten will begin a rehab assignment on Sunday for Double-A Portland against the Somerset Patriots on the road.
The 28-year-old has been on the 15-day injured list since April 8 with a right oblique strain.
He allowed one unearned run, two hits and two walks while striking out five in 3 ⅔ innings before landing on the IL.
The Sea Dogs and Patriots will play at 1:05 p.m. It is unclear yet how many rehab outings Slaten will need before he is ready to be activated.
Slaten has a 3.30 ERA in 84 outings (92 ⅔ innings) in his major league career.
The Red Sox have four left-handed relievers — Aroldis Chapman , Jovani Morán , Tyler Samaniego and Danny Coulombe — on the active roster. It’s possible the Red Sox will go with five righties and three lefties when Slaten returns.
“I think you like to have balance, you like to have lefties, but you may play a series where you don’t have many left-handed hitters and maybe it doesn’t make sense that way,” interim manager Chad Tracy said. “So I think just series to series as you go along, like kind of looking at that and deciding from there.”
Boston ranks 18th in the major leagues in reliever ERA (3.56).
Zack Kelly has stepped up nicely in Slaten’s absence with a 3.09 ERA and 0.94 WHIP in 11 outings. He has held opponents to a .214 batting average.
“He’s throwing the ball well right now. Really well,” Tracy said. “And you kind of look at the structure of our bullpen, it’s like we have four lefties and there’s four righties. So he’s going to throw leverage innings as well as Weiss (righty Greg Weissert ). ... The way it’s structured, all of them have to be ready to throw at leverage at times because it’s not a six-righty, two-lefty scenario. You just got to be ready to go.”
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