Oleksandr Usyk is a unique personality but is a unicorn as a boxer who is rapidly approaching legendary status

Oleksandr Usyk is closer to the end of his career than he is to the beginning. For much of his pro career, he fought as a cruiserweight, a division that, at least in the U.S., is often ignored.

But as he heads to training camp to prepare for his rematch for the heavyweight title against Tyson Fury on Dec. 21 in Riyadh, Saudi Arabia, a slow realization is beginning to settle in:

Usyk has firmly established himself as one of the finest boxers who has ever set foot in a ring.

If you doubt that, consider this:

• Won heavyweight gold at the 2012 London Olympics in a division that also included current undisputed light heavyweight champion Artur Beterbiev and cruiserweight title holder Jai Opetaia.

• Won a cruiserweight world title in his 10th professional bout.

• Became undisputed cruiserweight champion in his 15th pro bout.

• Became unified heavyweight champion in his third bout at the weight when he defeated Anthony Joshua.

• After defending his titles against Joshua in a rematch and Daniel Dubois, Usyk on May 18 became the undisputed heavyweight champion when he defeated Fury by split decision.

If you doubt that Usyk won that bout, well, argue with Fury. At a news conference in London on Wednesday to promote the rematch, Fury admitted Usyk had won in May.

"May was a fantastic fight," Fury said. "Oleksandr won the fight fairly and squarely."

Heading into the rematch, Usyk is 3-0 against the three best heavyweights in the U.K. and, arguably, the world. At DraftKings sportsbook, he's a -185 favorite to defeat Fury and retain his titles. The hulking Fury is +150.

A win over Fury in December would make him 23-0 and easily the greatest heavyweight of this generation. All-time? Well, it's difficult to fully and fairly rank a fighter from an all-time perspective while he's still active, it seems fair to say that with two wins apiece over Fury and Joshua and one over Dubois that he'd have to be considered one of the Top 10 heavyweights ever.

Usyk is not the kind to toot his horn, even though he's a funny, light-hearted guy.

He dressed as a hitman from the video game Agent 47 on Wednesday and was wearing gloves and carrying a briefcase. When asked what was in the briefcase, he took something out and walked over to Fury and placed it in front of him. Fury signed it.

Usyk then showed that it was a picture of him hurting Usyk in the signature ninth round of their first fight.

But he then didn't switch into a diatribe about how he's underrated. Asked about his motivation, he shrugged it off.

"I am happy to be here," he said in what was clearly not true because one could tell he'd rather have been pretty much anywhere else. "What is my motivation? I have no motivation. My routine and focus are my motivation. That’s enough."

He's no sure thing against Fury, and Fury was in control of the fight until Usyk nearly stopped him in the ninth. If Fury fights the way he did in the first half, and maybe adds to it, it's hardly inconceivable he could turn the tables.

Fury, of all people gets that. At the highest level, the difference between winning and losing is infinitesimal, and it's not going to take massive changes for him to close the gap.

"Last time it was very close," Fury said. "With ... a little more focus, a little less complacency, and I need to do what I have to do [and I can win it]."

Fury was up by three points on two cards and by one point on the third after seven rounds in the first fight. But Usyk won four of the final five on two cards and three of the final five on the third, with a 10-8 round in the ninth, to come back and get the win.

So Fury needs to be able to push it down the stretch, which is typically when Usyk is at his best.

“All I can do is prepare well, train hard, eat well, go to bed early, wake up early, listen to people around me, and then the rest is in God’s hands," Fury said. "I believe it will be my time this time. I believe all things that happen, negative or positive, are lessons. We must learn from them.”

Usyk is giving us a lesson on boxing each time he fights. He's fighting the best and winning, and closing the show impressively. He's considered "small" for this era of heavyweights, but he's never been down as a heavyweight.

He's shrewd in knowing when to press and when to back off. His adjustments are elite. He's never faded in a fight and he's never been outsmarted in the ring.

His record is screaming all-time great, though we've been slow to pick up on it.

It might be wise to start paying attention.