Jones was diagnosed with a UCL sprain to the right elbow Wednesday, Noah Hiles of the Pittsburgh Post-Gazette reports.
The Pirates initially announced the injury as soreness, but Todd Tomcyzk, the team's director of sports medicine, announced the formal diagnosis. He further elaborated that the ligament is stable, which has allowed Jones to avoid surgery for the time being. The announcement doesn't appear to change Jones' timeline to return, though there's a chance he will begin a two-handed plyo program in roughly three weeks.