David Haye has revealed Saturday's fight with Mark de Mori could be his last if he feels he is no longer the fighter he once was.
The former WBA heavyweight champion returns at London's O2 Arena after three and a half years out of the ring but is hoping to re-establish himself and again become a world champion.
Much of his absence has been enforced by a series of injury problems which included a career-threatening shoulder condition, and the combination of that and the likelihood that at 35 his reflexes - so crucial to the explosive style with which he built his reputation - will no longer be what they were has led to concerns he will struggle.
It would come as a significant shock if he did not stop Australia's little-known De Mori inside the distance, but even if Haye is capable of performing to the high level he consistently used to show it is unlikely to be visible on Saturday because of the many challenges posed by inactivity.
He now has a bigger build than in the past and believes this will avoid injuries recurring, but he also insists that if he feels he has declined he will be prepared to retire because there will be little point in fighting on.
"I'm not going to do this if I don't believe I can win that title," he said.
"If I'm in there and it feels so far away from me then that will be a consideration, even if I win the fight. What's the point? I'm not the type of person to get in the ring if I don't think I'm going to win the fight, I'd rather not do it.
"I'm not in boxing to get in there and lose because I'm too old. Unless I'm 100 per cent confident I can beat somebody, and become world champion, there's no point getting in the ring.
"I think I'll be able to tell (if I've declined). I've boxed for long enough to know that if I'm getting hit with shots I don't normally get hit with, that's a tell-tale sign.
"But that could be ring rust, it'll be hard to judge myself after one fight in three and a half years.
"I'm just focused on being fully prepared for this fight. I'm happy with where I am. (De Mori's) going to try and put it on me so let's have some fun."