Justin Slaten's elbow trouble ends his Red Sox season

Boston's bullpen just took another gut punch. Justin Slaten's flexor problem has led to a PRP injection, and according to interim manager Chad Tracy, that means his season is over. For a Red Sox team trying to hang on down the stretch, losing a key relief arm for good is the last thing this pitching staff needed.

This has been the story of Slaten's 2026 season from the jump. He'd been dealing with elbow issues all year, and the club shut him down for a stretch in mid-August with right elbow inflammation. Tracy said at the time the Red Sox weren't going to ramp him back up until they saw "complete resolution of symptoms" — a phrase that in hindsight reads like a warning sign nobody wanted to say out loud.

It's a rough way to close the book on a guy who'd carved out a real bullpen role in Boston. Slaten went 2-4 with a 4.24 ERA, 25 strikeouts and 10 walks in 2025, working himself into a trusted relief arm for a team that needed one. This year never let him build on it — one IL stint bled into the next, and the same elbow that shut him down in August is apparently the reason he's not walking through the door again this season.

A PRP injection is a step teams take when they're trying to jumpstart healing without going under the knife — plasma spun from the pitcher's own blood, injected into the site to accelerate recovery. It's not a season-ending procedure by itself, but paired with the timing here, right as Boston is trying to lock in its playoff bullpen, it reads as the organization choosing to shut things down for good rather than push a hurt arm through October.

That leaves the Red Sox thinner in a bullpen that was already stretched by injuries all year. Boston has had to keep shuffling arms in and out of high-leverage spots, and every time one name goes down for good, the margin for error in these final weeks gets a little smaller. Whatever late push this team makes, it's going to have to happen without Slaten in the mix.