We discussed this in a sports injury post on the board

I developed an impingement about 3 years ago

Dr said, as long as I can tolerate the pain, avoid surgery

Can't remember the specific poster, but somebody here had the surgery and said they would elect to not have it given a chance to do it over again

9 months of rehab and the shoulder will never be 100%

XRays showed my impingement is caused by loose cartilage sitting in the joint

I would say yes, the high release is the issue...limiting his rom on jump shots is an effort to alleviate the pain from a high release

...or have the surgery and bag the whole season...