Anthony Joshua vs Wladimir Klitschko: A fight that, for the loser, will be one too soon or one too late

The talking will stop on Saturday as the two giants of heavyweight boxing face off at Wembley in front of 90,000 people

It's youth vs experience with Joshua's 18 professional fights to Klitschko's 68 (Getty)

When Anthony Joshua won the world title last April he was a novice in his head, in his movements and in the ring. That big kid has gone, he vanished behind a year of hard education.

When Wladimir Klitschko tumbled from his heavyweight recliner in late 2015, hitting the floor in a puff of magic smoke on the night, he was too old to continue, finished in the game he dominated and retirement was winking seductively at him. That old geezer has gone, replaced by a Wladimir not glimpsed for a decade.

This is a fight of two contrasting figures, their devoted teams and the total desertion of boxing sense and reason. Joshua does not know enough, Klitschko is too old, both facts in the fighting business, and somewhere in the middle of the claims, dreams, hype and glorious denial, a perfect fight is likely. It has felt like a real fight for a long time, their week together has only reinforced my belief that too much pride can now be added to the expectation and that is always good.

On Saturday night under the inevitable twinkling canopy of 90,000 hot telephone flashes, the two fighters will jog to the ring and the smooth claims by the men from the inside of the rival camps will no longer matter; there will inevitably be harsh truths mixed with blood and thunder as the delusions of both men risk shattering. It will either be too late or too soon, the simplest of fights are never complicated – and Joshua against Klitschko is in many ways the simplest of fights.

It is possible that Joshua is the finest 18-fight boxer in the heavyweight division's beautiful history. There is no doubt that Klitschko is the greatest 68-fight heavyweight in history. It is, make no mistake, a fight of extremes. One boxer is 27, one guy is 41, they both won Olympic gold medals, separated by 16 years, and as they have slowly come closer and closer this week there still remain some classic unknowns. There has not been a single moment of odd insight revealed as they have performed their contracted rituals in public; I have not spotted a furtive glance, not heard a slight.

Joshua has changed since last year, he acts differently than the man that biffed his way through three world title fights during the last twelve months, rarely having to dab the sweat from his brow. In the gym Joshua is a sponge, living a stark life in pursuit of boxing greatness. His devotion to learning his art, to becoming a better boxer has been furious to witness. His raw statistics are truly misleading and if he was as inexperienced as he seems this fight would be an unpleasant massacre. There are some that believe it will be.

Klitschko comes loaded with a brain of ancient boxing tricks, a history packed with every possible outcome. Big Wlad has been dropped, stopped, rocked, defied odds, boxed like a dream and he has total recall of every second of a truly remarkable career. If his legs work as smoothly as his mind this fight holds no mystery, Joshua would have no chance. In bewildering contrast Joshua only has a tiny list of boxing memories, none of them based on hardship. Joshua will be fighting in an alien place, probably from the first bell and the old man of Kiev will know that. "I will help you get over losing," Klitschko cheekily offered on Thursday. "It is not so bad, you recover quickly, don't worry."

However, there has to be decline somewhere in Klitschko's towering frame and Joshua will target the weaknesses, exploit the flaws. It could be the pace, it could be the power and it is more likely to be a combination of the both. Klitschko will have to fight, will be forced to fight at an uncomfortable speed. Well, that is the thinking. Joshua is certainly capable of being a bit wild and will probably need to take a risk or two to unsettle Klitschko. A comfortable Klitschko will return to Germany with the belts, a savage Joshua will be celebrating inside four rounds.

"I looked at him, he looked at me - two tall heavyweights, no need for drama," Joshua said after the traditional eye-to-eye that followed the weigh-in at Wembley Arena on Friday afternoon. Big Wlad left without a smile, Joshua departed and for the very first time all week there was a different look on his face, part boredom and part intensity; he simply needs to fight. "No more talking," he added as he was shuttled through the backstage at the grand old hall to a van and the start of about 30 hours of waiting. At 10:01pm on Saturday we will all find out whether Joshua is ready and whether Klitschko is finished; Joshua is ready, he just needs a steady heart once that first bell tolls, but I'm not as convinced Klitschko is ready to quit just yet. In other words, this will be a proper fight and when they have stopped throwing punches Joshua's life will never be the same again.