If he has a tear in his rotator cuff, does he know when it happened? Was he quite inactive while he had Covid?

I think maybe, before searching for a post Covid clinic, he might want to be evaluated for a frozen shoulder. Sometimes, even with a relatively mild injury, the muscles and joints will stiffen up dramatically from non-use. I had a friend who experienced this after a long illness, even without any apparent injury.

The solution was a fairly long course of progressive exercises to get the movement back, as well as repeated evaluation and manipulation by a PT.

Did any of the docs he saw suggest this as a possible issue?
Sue