Not saying he needs nannying, he just needs to be given a purpose. A reason to get up in the morning and a reason to go to bed at a reasonable hour. Something to give him pleasure and a reason to stay healthy. And football is as close to his heart as anything will be. If he can be given a football role that is serious and important, it's better than him having nothing. Surely football as a sport can give him that opportunity. It would be a shame if the sport can't help one of it's legends in this way.
You idea is a good one, once he becomes sober. But personally I think at the present time it would be of little use. His purpose should be to get sober and stay sober.
His most important goal at the moment is to accept he is an achoholic, and that he can no longer control his life because of his drinking. He needs to re-evaluate his whole life, sort out his demons and his head and needs to accept the only way he can do this is without that drink. This takes time - a day at a time - not a quick 5 week stay in rehab. He probably feels euphoric at the moment, as his body is free of the drink, but unless he takes control then I see him back in rehab perhaps for the last time.