Anthony Joshua will not simply bulldoze his way through Francis Ngannou and must seek to wear out the mixed martial artist-turned-boxer before landing any knockout blow, according to Eddie Hearn.

Ngannou may have lost the element of surprise after a staggering professional boxing debut last October when the former UFC heavyweight champion knocked down Tyson Fury before losing a debatable decision.

He will look to prove his performance was no fluke on March 8 against Joshua, who hopes to put himself in the shop window for a crack at British compatriot Fury or a trilogy meeting against Oleksandr Usyk.

But promoter Hearn thinks Ngannou poses a sizeable challenge despite his novice status and is unlikely to fold as so many of Joshua’s past opponents have done when confronted by his frightening punch power.

“It’s definitely a fight with a lot of jeopardy,” Hearn told the PA news agency. “You really have to be on your guard for this fight, you’ve got to be razor-sharp.

“Francis has surprised everybody. He’s one stubborn competitor and it’s not going to be easy, you’ll have to knock him down and keep banging and banging and banging away.

“This isn’t going to be one hit on the chin, clearly he’s an immovable object with a fantastic chin and big, big, big power.

“You’ve got to be really smart in this fight – don’t get hit, break him down and hopefully he’ll go over like a big tower and we can just move on.”

The fight against Ngannou in Riyadh will be a fourth in the space of 11 months for Joshua (27-3, 24KOs), who is trying to boost his hopes of becoming a three-time world heavyweight champion.

He is therefore positioning himself as first in line to face the winner of the rearranged clash between WBC champion and long-time rival Fury and Usyk, the WBA, IBF and WBO champion who has beaten Joshua twice.

The pair go head-to-head on May 18 in the first undisputed world heavyweight title fight of the four-belt era and Hearn is keeping his fingers crossed it is Fury who prevails.

“I really want Fury to win his fight because if AJ can do a job on Ngannou, it just sets up the biggest fight in the history of the sport in my opinion,” Hearn added.