He missed 4 games to injury and 54 games due to "weed addiction".
While you can absolutely argue that he was an idiot to give up a career for weed you can look at it in other ways too. He was standing for what he believed in. He would rather smoke weed than play football. Within all of that is the fact that he is a millionaire who if he was smart about it doesn't matter if he ever played another down in the NFL.
Regardless of all that, the fact is that almost all of the games he missed were due to weed, this is no longer an issue, so, the question that seems to be being ignored is what makes you believe that he will have an issue staying on the field since the issue that kept him off the field (voluntarily or not) is now gone?