It's (as far as I know) unheard of that a top athlete manages to return to his/her sport after a major heart issue. As much as I want to believe he'd one day be back on the pitch at a top level, I can't imagine a club would let him back on the pitch no matter how much he wanted it. Big difference between your average joe doing a normal job after something like this and athletes that have to train and put a strain on their body beyond normality virtually every day.