A nervous Eddie Hearn expects a mentally "draining" fight for Anthony Joshua when he takes on Oleksandr Usyk in their highly-anticipated showdown at Tottenham Hotspur Stadium.

Joshua has height and reach advantages and will almost certainly be heavier when he defends his WBA, IBF and WBO heavyweight titles this weekend, but Hearn is among those to anticipate the toughest test of the Briton's career.

That is because of a breathtaking skill set possessed by the Ukrainian who won gold at London 2012 the day before Joshua in the division below, including deft footwork, blurring hand speed and stamina few others can match.

Usyk, a former undisputed world cruiserweight champion, is therefore regarded by Hearn as the most demanding of foes for Joshua, who has avenged a defeat to Andy Ruiz Jr and risen from the canvas to stop Wladimir Klitschko.

Joshua's career has been overseen by Hearn since turning professional eight years ago and although the Usyk fight was understood to be the last on the existing contract, the two parties have come to a new arrangement.

Hearn said: "It shows the quality of Matchroom and the job we've done as a team for him. He's very comfortable with us, he trusts us, that goes a long way for Anthony Joshua and he also has a tremendous amount of loyalty.

"We've never had one argument, we've never had one dispute, in eight brilliant years. So if it's not broke then don't fix it and we're very proud that he's extended his contract with us for the rest of his career."

While Hearn ended a long-term partnership earlier this year with broadcasters Sky Sports, moving to streaming service DAZN, it is his old employers who will be screening Joshua-Usyk in the UK and Ireland on pay-per-view.

Joshua will be a network-free agent after this weekend, but Hearn added: "People presume because of the deal that we'll bring him over to DAZN. At the end of the day we'll make the right decision for Anthony Joshua, not a decision that will benefit Matchroom."