Treinen underwent surgery on his right shoulder labrum and rotator cuff Friday, Juan Toribio of MLB.com reports.
Treinen fought through multiple shoulder injuries in 2022 and underwent surgery in order to manage the lingering pain. The Dodgers didn't provide an immediate timetable for his return, but considering the rehab process typically takes around 10 months for this surgery, it is reasonable to think Treinen will miss the entire 2023 campaign.