While he doesn't care what fans think, this is the other side of the pay for play. He is more or less an employee, whether by definition or not. As an employee of my company, if I do something in my spare time that negatively impacts the future results of the company, there are consequences, as there should be.
Eh, you have to have a life. If you have a job where you have to stand and walk and you tear an ACL playing tennis over the weekend or hiking with your wife, it's unreasonable to have consequences.
On a camping trip, my father tore his Achilles simply batting a ball back and forth with my 5 year old brother. It wasn't even a sports ball. It was one of those $1 plastic bouncey kiddie balls that you get in one of those dump bins at the grocery store. He had to lunge forward a bit to keep the 'rally' going and POP.
If you're an athlete, ATV'S, any two wheel vehicle, non-goverened engine go-carting, sky diving, jet skiing, alpine skiing, rock climbing, etc. shouldn't be allowed.