Relaxed or disinterested, sad or comfortable, mean or psychopathic. Take your choice. Mike Tyson has long since grown tired of those who judge him, and has even less interest in assessing his ability inside the ring or justifying his life to those who might seek to condemn.

"I've grown old too soon and smart too late," was the headline writer's dream quote of the week as Tyson went through perfunctory final preparations for yet another multimillion-dollar pay-day, this time against an overweight and strictly limited Dane, Brian Nielsen, in Copenhagen tonight (Sky Box Office from 8 p.m.).

It might as well have been: "You'll see what happens, I don't really care."

The fact that Tyson, now 35 and going into his 54th professional fight, chose to employ a specialist fitness conditioner for this engagement, yet still weighed in at 17st 1lb, an astonishing 151/2lb heavier than at any stage of his career, prompts suggestions that he may have grown tired of the athlete's life. Exactly how heavy Tyson became during the year since his last fight against Andrew Golota has not been revealed, but it is safe to assume he was more unfit than at any stage of his life.

As far as his boxing future is concerned, the overwhelming conclusion to be drawn about Tyson just before this fight is that he is either tired of the sport or so contemptuous of his opponent that he sees his preparations as little more than an irritating intrusion.

Nielsen, in contrast, has been promoted brilliantly. In nine years as a professional "Super Brian" has amassed 62 wins and one defeat and grown rich. That almost all his opponents might charitably be described as journeymen and that he has benefited from more than the occasional home-town decision is beyond dispute, but he is what is known in the trade as "a ticket seller".

The immensely popular and personable Nielsen is already secure financially, owning Denmark's biggest removal company, but has been keen to procure one more huge purse before his career is over.

Though publicly he makes the right noises, there is the underlying suspicion that Nielsen, (36), is looking only for retirement money. The truth is that this should be one of the easiest contests of Tyson's career unless he unravels so dramatically as to make nonsense of his advantages both as a boxer and a puncher. The only big names on Nielsen's record, Larry Holmes and Tim Witherspoon, were so far past their sell-by dates as to be well nigh obsolete by the time they fought in Denmark. Nielsen is 18st 7lb, a shuffling spoiler who is strong but lacks credibility as a man about to end the career of a once great fighter. His only chance, perhaps, is that Tyson has taken him too lightly.

In April, Hasim Rahman knocked out a complacent and patently out-of-condition Lennox Lewis to take the world heavyweight title, and there is a feeling that history would repeat itself in the Parken stadium if Nielsen were a more capable performer. A disinterested fighter can be a vulnerable man.

Nielsen draws heart from the parallel and claims to have floored Rahman twice during sparring sessions. The Dane says of Tyson: "He doesn't intimidate me. He surrounds himself with a big entourage and so much bullshit that it means nothing. I know he has a good punch, but that is the only thing he has and I have a good chin.

"There will be 20,000 people cheering for me and that will help. I'm not afraid of being punched, only afraid of looking bad. Boxing has been good to me and I am going in there knowing I will win this fight."

Tyson's trainer Tommy Brooks, a respected figure in the sport, is a realist and a conspicuously level-headed figure in the Tyson camp. He played down the weight issue, but admitted Tyson's time out of the ring could be a factor. "Whenever any athlete has time away from what he does, it affects him," said Brooks. "But we have a strategy for victory. In the past Mike has just gone out there blasting, but now he is thinking.

The jury is still out on Tyson's fitness. But in a fight between an old boxer going through the motions and a lumbering national hero, class should prevail and Tyson's power should bring him a hollow victory inside three rounds to keep alive his hopes of regaining the world heavyweight title.