The Red Sox are designating veteran reliever Tommy Kahnle for assignment, reports Chris Cotillo of MassLive. Cotillo was also first to report that Boston will recall lefty Alec Gamboa from Triple-A Worcester tomorrow.

There’ll probably be more moves coming. Starter Connelly Early exited after four innings tonight with discomfort at the back of his elbow. Interim manager Chad Tracy said the rookie southpaw will go for imaging tomorrow (via Gabrielle Starr of The Boston Herald). Even if that comes back clean, it seems likely the Sox would play things cautiously and place him on the injured list. He’s only scheduled for two more starts before the All-Star Break.

Early had cruised through four scoreless innings before his premature exit. Boston wound up using five relievers in as many innings the rest of the way, as the Nationals teed off on the bullpen for eight runs. Danny Coulombe, Greg Weissert, Justin Slaten and Kahnle all gave up runs. Only Rule 5 pick Ryan Watson managed a clean inning.

Kahnle took 30 pitches to labor through a four-run eighth. He gave up four hits, including a CJ Abrams home run. The 36-year-old righty has surrendered eight runs over nine innings since the Sox called him up in early June. He has allowed 12 hits and issued six walks while striking out five.

The Sox also simply need fresh arms for an overworked bullpen. Kahnle wouldn’t have been available for tomorrow’s matinee finale. Weissert tossed 28 pitches and is probably also out of action. Coulombe just pitched for a second straight night. Weissert has a minor league option remaining; Coulombe does not.

Kahnle is likely to wind up on waivers this week. He’d have the right to elect free agency if he goes unclaimed. Kahnle pitched pretty well in Triple-A, working to a 1.40 ERA while striking out a quarter of opponents over 19 1/3 innings before his promotion.