You don't sound like you're guessing?I he is truly given the all clear than he's fit for any side. If not....he has by definition more than an ordinary chance of dropping dead on the pitch and will therefore have to retire. There is no middle ground here.
Could there be some instances where a player could need surgery and then receive the all clear? Or could he have a condition where things are ok at the moment, but he needs constant monitoring in case things change?