Former two division champion Tony Bellew believes Oleksandr Usyk is the "best boxer" that Anthony Joshua is ever going to face in his career.

Joshua will defend his WBO, IBF, WBA, IBO titles against Usyk, a mandatory challenger, on September 25 at the Tottenham Hotspur Stadium.

Bellew retired from the sport in 2018, after suffering a vicious knockout loss at the hands of Usyk.

Regarding his ability to pull off the upset next month, Usyk has been written off by a lot of critics.

Usyk unified the entire cruiserweight division in 2018.

He moved up to the heavyweight limit the following year.

The unbeaten boxer's run has not been as impressive since jumping to a higher weight class

Back in October of 2020, Usyk had a much tougher time than expected in winning a twelve round unanimous decision over division veteran Derek Chisora.

In terms of boxing skills, Bellew backs Usyk as being the best boxer that Joshua could step in the ring with.

But, that's not the same thing as saying Usyk will be the hardest fight for Joshua, says Bellew.

“I’ve been saying it. This is the best boxer he’s ever going to face in a boxing ring,” Bellew told IFL TV.

“The best natural boxer, without a shadow of a doubt. It’s not potentially his hardest fight because Tyson Fury’s potentially his hardest fight. But the best boxer he’ll ever face? Yes.

“For what he’s capable of doing, how good he is, how technically good he is, the arsenal of punches that he’s got. He’s outstanding as a boxer. Standalone, without a doubt. He won’t face a better boxer than him.”