The Dodgers have halted right-hander Brusdar Graterol’s throwing program for the time being, manager Dave Roberts announced to the team’s beat Wednesday night (X link via Fabian Ardaya of The Athletic). While there’s no new injury or setback of note, Graterol still feels discomfort in his arm when throwing and isn’t bouncing back as well as the team had hoped.

Graterol, one of the Dodgers’ top setup options, has been out all season after experiencing shoulder pain during spring training and being diagnosed with inflammation. He’d already been moved to the 60-day IL early in the season, but since the Dodgers opened the season early with their Seoul Series against the Padres, he was still ticketed for a potential mid-May return. That no longer seems feasible. Roberts didn’t offer an exact timeline but indicated it’d be a “long program” to get Graterol back on a big league mound.

It’s unwelcome news for a Dodger bullpen that ranks 19th in the majors in ERA (4.07), 26th in FIP (4.52) and 16th in SIERA (3.81). Graterol was a major part of the bullpen last season, firing 67 1/3 innings with a pristine 1.20 ERA. The 25-year-old flamethrower picked up 19 holds and seven saves along the way. He fanned just 18.7% of his opponents but also delivered a brilliant 4.7% walk rate and superlative 64.4% ground-ball rate. In four seasons since the Dodgers acquired him from the Twins in exchange for Kenta Maeda, he’s pitched 173 2/3 innings with a 2.69 earned run average.

The Dodgers have a handful of relievers throwing well, but the rest of the bullpen has struggled extensively. Closer Evan Phillips (0.93 ERA, six saves), setup man Daniel Hudson (2.45 ERA, five holds) and long man Ryan Yarbrough (3.52 ERA, 23 innings) have all had strong starts to their season. Lefty Alex Vesia has allowed only three earned runs in 12 1/3 innings (2.19 ERA), but he’ll be hard-pressed to sustain that pace based on his dismal 19.6% walk rate thus far. Righties Joe Kelly, Ryan Brasier and Michael Grove are the only other L.A. relievers with even nine innings pitched this season; all three have ERAs of 5.59 or worse.

The Dodgers have already used 15 different relievers in the young season. No team in baseball has used more, although both the Mets and Astros are also at 15 apiece. The continuity and stability afforded by a healthy Graterol would be a boon to Roberts’ relief corps, but it seems that’s a ways off from being a realistic possibility. The Dodgers tend to explore the trade market for bullpen help just about every summer — as do most contenders — and if Graterol faces an especially lengthy absence, that’ll only add to their urgency.