The Los Angeles Angels are still 10 days away from knowing how long they'll be without Shohei Ohtani, but Mike Scioscia said Monday that the team remains "very optimistic about the prognosis."

The club is hoping that injections of stem cells and platelet-rich plasma will heal his injured elbow without the need for surgery. Ohtani was diagnosed with a Grade 2 sprain of the ulnar collateral ligament on his right (pitching) arm on June 7.

"Initially he was obviously very disappointed," Scioscia said. "I think that as he's gone through this first week of therapy, I think he's come to grips with it and understands exactly what the process will be. Our medical staff and doctors -- we're very optimistic."

The Angels are hopeful that PRP and stem cells can heal Ohtani's UCL without the need for Tommy John surgery, which would potentially keep him away from the starting rotation until the start of the 2020 season.