How old is the kid, how long was he side lined?
Depending on the severity and duration he might have lost some muscle tone, etc...
I am not commenting on Russian coaches, I think I have yet to run across a Russian, coach or other
But I can give you one tool: Bach's Flower remedies, especially 'Rescue Remedy'
While I am solidly torn between reason and myth, I have tried that stuff myself, after reading about it from dog rescuers, horse people and even gardeners: you put that stuff under your tongue it works right then and takes the edge of anxiety! (even with an alcohol content of 70%, with 4 drops, I don't think you can do any damage!)
Of course as parent, we are always doing the high wire act: When is the kid BSing us, when do we have to switch to Momma Bear mode and advocate for them....
I think since he wants to skate, you should find a way to deal with the problems and not make him quit just yet...
On the other hand, you could find something else for him to do for the summer, then see where he is when the season starts back up....
But I find it impressive that he is willing to endure the anxiety to skate. Nothing I see at my house.....