I think he first has to mourn his loss. He also needs to see and accept the risk of those other sports. He likely has not accepted that for him, the risk of play is just too high. He likely thinks others who are restricting him are the problem, not his own concussion history.

He may also be missing the adrenaline/dopamine high. Finding an activity that can induce that response would be good.

The fact that he is so affected by the stress of seeing a soccer game suggests that his brain is still struggling with stress being a big trigger. This shows the effect another concussion could have. It sounds like this may be part of a personality change like I went through. The injured party does not realize their personality has changed. It is tough. They react differently. They have less tolerance for conflict.

I wonder if it would help for him to spend some time with a counselor to help him learn to better tolerate these issues ?

Is there a neuro-rehab clinic hospital nearby that may have such a trained counselor ? I know that they exist to help people who have lost functions. That grieving process can be difficult.

I wonder if UPMC Concussion clinic could help you with a phone consult ?
http://www.upmc.com/Services/sports-...s/experts.aspx

I know the struggle you are dealing with because I lived it. But, I was fighting a concussion caused seizure disorder and on meds for it so I was more self-protective about staying away from risk. But, it can be miserable.

My best to you.