It wouldn't be very succesful if he did IMO

Mainly cause his game was built on speed, agility, reflexes, power. Never cared about fundamental skills much, especially as his career went on. He's I think 32 now, is he out of prison yet? Either way, by the time he got out of prison (if he's still in), lost the 50 or so pounds, and took on a couple of no hopers to ease his way back in, he'd be about 34 or older by the time he tried to make a meaningful fight. His power might still be there to some extent but at that age it seems unlikely the speed, and reflexes would be the same.

Or like others have said he could speed up the process by coming back at lt heavy.

Superfight: Tarver-Hamed.