Hill was diagnosed with a flexor strain, David Vassegh of AM 570 LA Sports reports.
Hill exited Wednesday's game due to forearm tightness, and a subsequent MRI revealed the veteran southpaw is dealing with a flexor strain. He had a PRP injection Thursday to help the healing. While the issue isn't expected to require surgery, per Vassegh, Hill likely won't be able to resume throwing for 3-to-4 weeks. He's still hoping to pitch again this season, though he has a lengthy recovery process ahead of him.