How does Anthony Joshua become No. 1? By beating Tyson Fury

Joshua explains strategy change since Ruiz loss (1:24)

Anthony Joshua reflects on his loss to Andy Ruiz and explains his change in training since that fight. (1:24)

Regardless of how he does against Kubrat Pulev on Saturday, Anthony Joshua is still likely to trail rival world champion Tyson Fury in most people's opinion of how the heavyweight division stacks up.

Joshua might own the majority of the belts -- WBA, IBF and WBO -- and, if he beats Pulev in London (the fight will be shown live on DAZN in the U.S. and more than 200 countries and territories around the world), he will outscore his fellow Englishman Fury in world title wins by nine (and one defeat) to two (and one draw).

But Fury's win over Deontay Wilder in February, following a draw two years ago, and on points over Wladimir Klitschko five years ago, have been enough to knock Joshua off top spot in the ESPN divisional rankings.

Joshua (23-1, 21 KOs), from Watford, England, had been regarded the heavyweight king until he lost his belts to Andy Ruiz in a shock stoppage loss in June 2018. The 31-year-old regained them on points a year ago but George Groves, the former WBA world super-middleweight champion who retired in 2018, said Joshua needs to do more if he is to be remembered as the era's dominant heavyweight.

"AJ just has to beat Tyson Fury to establish himself as the No. 1 in the division," Groves told ESPN. "He could ice Pulev in a minute and it won't be enough. Pulev is a hard nut, but it doesn't matter. If AJ iced Wilder in a minute it still wouldn't be enough. The change in perception of Tyson Fury has been incredible from where he was a few years ago and he's become one of the most likable heavyweights in the world.

"The heavyweight division is rocking at the moment; people want to see other heavyweights like Derek Chisora and Dillian Whyte, too. The only person's whose popularity has suffered is probably Joshua because it couldn't have got any better. But now there's Fury."

Promoters have been talking about the possibility of Fury-Joshua happening twice in 2021, but there are obstacles to overcome before that becomes a reality. Wilder (42-1-1, 41 KOs) insists he is due a third fight with Fury (30-0-1, 21 KOs), due to a contract clause, and the American has taken legal action. Oleksandr Usyk (18-0, 13 KOs), the former undisputed world cruiserweight champion from Ukraine, is also pushing to face Joshua next as mandatory challenger for his WBO belt.

David Haye, former WBA world heavyweight champion, said Joshua must fight Fury even if it means facing others beforehand.

"I don't see the Joshua-Fury fight happening for a while because of COVID-19," Haye told ESPN. "I think it will be a travesty if they fight without a full crowd. It will disappoint 100,000 potential fans who could watch it live.

"It's down to opinions -- and everyone has got one -- who is No. 1, but they need to fight at the right time. Both fighters need to stay busy and for AJ, Usyk makes sense because it fulfils his WBO situation, obligation, and taking care of business. Tyson Fury has still got unfinished business with the WBC and Deontay Wilder so it's up in the air when he fights Joshua or Wilder. I've got both Fury and Joshua as joint first place at the moment before they fight each other. You have to understand how Joshua has got all the belts and how Wilder has shot up in people's expectations by beating Wilder emphatically."

Peter Fury, uncle and former trainer of Tyson Fury, has warned Joshua not to overlook Pulev after the Bulgarian outpointed his son Hughie two years ago.

"Pulev is ... a very good boxer, he will have his own ideas against Joshua, he's very awkward and he will put on a good show," he told ESPN.

The English boxing trainer also said Usyk will play a major role in future fights involving the likes of Joshua, and possibly his nephew.

"Usyk will play a big part. Everyone knows he's a good boxer but some people are saying he's a bit on the small side for heavyweight, but I don't think so," he added. "In Usyk's defense, he's 6-foot-3, so he's quite a big man, and he's very athletic, so that's his natural weight. He's got power and he's not that small if you look at the likes of Evander Holyfield, who came up from heavyweight to be world heavyweight champion, so that proves it can be done. He's very agile, and I don't think the size matters.

"You can't say who will win [Fury vs. Joshua], everyone is bringing something to the table. What makes the heavyweight division so interesting is that they are fighting [in 2021] and when they do it will be clear to everyone who is the best. That's why people are guessing at the moment, so let's get them fighting each other to see."

Daniel Dubois, who was recently stopped by English rival Joe Joyce, fancies Fury over Joshua judged on recent form.

"Fury is probably at the top right now, and then after that it's Joshua," Dubois told ESPN. "They have proven their worth and beaten everyone in front of them, everybody they have needed. Now they need to fight each other, and they probably have to do it twice to sort out who is definitely better,

"I think Fury should have the better of it, but I'm not certain, Joshua still has a chance. Based on his last appearance, Fury should use his reach, skill and experience to win."