Anthony Joshua is set for one of his most unique challenges to date this weekend, as he squares off against the undefeated Oleksandr Usyk. 

The Ukrainian great announced he would be making the jump to heavyweight after defeating Tony Bellew in 2018. Since then, he's gone on to notch up wins against Chazz Witherspoon and Derek Chisora to keep his perfect record intact. 

However, the former undisputed cruiserweight champion will have to answer some very different questions on Saturday, when he faces what is almost definitely the biggest—and highest-profile—test of his career.

READ MORE: Anthony Joshua vs Oleksandr Usyk: Date, Odds, Tickets, Stats, Live Stream, Card And Everything You Need To Know

Unsurprisingly, bookmakers generally have Joshua as the favourite, as does much of the boxing world. Despite that, Usyk's pedigree as one of the sport's best has led a fair few to believe an upset could be on the cards. 

Here's how the biggest names from the sport are expecting things to play out at the Tottenham Hotspur Stadium. 

Dillian Whyte 

Whyte's history with AJ has been well-documented, with the buildup to their own meeting in 2015 becoming particularly fiery. 

Joshua won via seventh-round TKO on the night, and 'The Body Snatcher' has backed his fellow Brit to end things in similar fashion this weekend. 

"I think it's a great fight, but in my personal opinion, I think Joshua will stop him in the first five, six, or seven rounds." Whyte told 5 Live Boxing.

"Usyk will start fast, and Joshua will be a bit cagey because he’s a southpaw, he’s lighter, and Joshua can also sometimes lack confidence in fights.

“He can get caught up in, ‘Oh, he’s a good boxer, the guy's this, the guy's that,’ and he's still in this learning period where he's learning things and trying stuff out as well.

"Hopefully, he goes back to the old him and starts pressing Usyk and being the bigger, stronger guy and starts backing him up and starts hitting him with stuff early. I think he can get the job done early."

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George Groves

Former super-middleweight champ George Groves agreed that the significant size difference means Usyk will need to make his opponent miss throughout the fight. If he manages to do that, though, Joshua could have a huge task ahead. 

Speaking to 5 Live, Groves explained: "Technically, Usyk is brilliant. He showed that in unifying the cruiserweight division in great fights and I believe he could be Joshua's toughest test to date.

"The only question mark for Usyk is: Is he big enough to compete with AJ? If Usyk keeps a high pace and makes Joshua miss with a lot of shots, that will work to Usyk's advantage as he has probably got a better engine. You don't want Usyk having any confidence.

"Joshua is a phenomenal athlete with tremendous punching power and strength but has a tendency to tire out if the pace is uncomfortable for him. If I was Joshua, I would take control of the ring and try to dominate and bully off the front foot.

"Usyk will want to be off the back foot for the first couple of rounds, then try to pepper Joshua.

"This is the first fight when I wouldn't be surprised if Joshua got beaten."

David Haye

David Haye was has been far more straightforward in his pre-fight prediction. When asked about how much trouble Usyk could cause AJ, he told iFL TV: "Not much, I don't think.

“If Anthony Joshua decides to have a tit-for-tat boxing match – just jabbing and trying to score points – then he’d have some trouble, but he’s not stupid enough to do that.

“He’s just 'gonna use his beautiful jab, use his height and reach advantage, use his size and weight advantage and his punch power advantage.

“His physical athletic advantage, his advantage of being able to receive punches from big heavyweights.

“He’s just better all-round and it’s just gonna be pretty devastating.”

Chris Eubank Jr

Despite acknowledging Usyk's undoubted talent, Chris Eubank Jr echoed Haye's comments that AJ's power will be too much to overcome. 

“Usyk is extremely smart and can certainly box, he has shown that at cruiserweight but I just don’t think he has the size to beat someone like Anthony." Eubank told The Mirror.

“And Anthony has shown that he is smart too, he demonstrated that in the rematch with Ruiz where he really boxed well.

“So personally I would fancy Anthony to win that fight.”

Tyson Fury

To the annoyance of just about every boxing fan in the world, this fight is very much a 'plan B' to Tyson Fury's long-awaited meeting with Joshua. 

The Gypsy King shut down any hopes of an upset, telling Seconds Out: I think he walks straight through Usyk.

"People are trying to build it up as a scary fight but he didn’t have the power to halt cruiserweights like Mairis Briedis or whoever else he fought."

John Fury

John Fury made a similar prediction to his son, once again citing the sheer size disparity. 

“Usyk won’t be able to hit hard enough to bother him because he’s too small. He’ll walk straight through." He said when quizzed by Boxing Social.

"I think AJ will stop him quicker than anybody else. I think AJ will walk straight through him. I do.

“One’s a cruiserweight, one’s bulking up. And if he bulks up to try and meet him head-on, forget about it. That’s why there’s weight classes. A good big one will always beat a good little one. And AJ is a good big one.”

Frank Warren

Fury's UK promoter hedged his forecast a little more. While initially siding with the favourite, Warren warned that if the fight moves into the later rounds, then the balance could shift. 

“Anthony Joshua must be the favourite for the fight. He’s the bigger guy and he’s a bigger puncher." Warren told iFL TV.

“Having said that, if he doesn’t get rid of him, and if he’s still there after five or six rounds, then it gets to the end of the fight, if that goes 12 rounds, I would fancy Usyk to get the decision because to get there, he’s going to have to outbox him.

“He proved it at cruiserweight. He was fantastic, and he’s made his mark in that weight division. He was a superb cruiserweight."

Anthony Joshua will meet Oleksandr Usyk this Saturday (September 25), with ring walks expected around 10pm UK time.