If he was 'old' in the sense of unable to defend himself, weak, unfit, history of being hit a lot, slow, unskilled and from a lower-tier level I'd certainly want him to retire, for his own good. But he's none of the above. Whatever he decides I wish him the best. I think he'd beat Stevenson, so there's a belt right there - trouble is he'd need to face Kovalev again to unify !!