After watching History Channel's "Men who built America", seeing how ruthless they could be whilst hiding behind their philanthropy (I won't vouch for the historical accuracy), I couldn't help but make a connection. It's all about winning against the other guy and it's not something that just goes away.
It's clearly not in LA's personality to just go away. Life's a race. Since he's out of the sport, he'll reinvent himself in a different field, probably business (biomedical? cancer treatment?), and possibly go after sport in general. He may bring tremendous amount of money into it and make everyone utterly dependent on him. He could create an even bigger following than ever before.