Heavyweight contender Jarrell Miller believes former two-time world champion Anthony Joshua “made a mistake” by selecting Otto Wallin as his next opponent.

Joshua will face Wallin in the main event of a big card on December 23 in Saudi Arabia.

As part of the undercard, Miller will return to the ring against Daniel Dubois in a crossroads fight.

Wallin has a single loss on his record - a tough twelve round unanimous decision loss to current WBC world champion Tyson Fury in September of 2019. During that fight, Fury sustained two serious cuts around his eyes from legal punches and there was real concern of a potential doctor's stoppage.

Miller could see a scenario where Joshua's mental state will begin to crumble if the durable Wallin continues to make it a real fight, round after round.

“I feel honestly that AJ might have made a mistake with picking Otto Wallin. Even though Otto Wallin is not a one-punch knockout kind of guy, he is durable and he comes to fight," Miller told SecondsOut.

“He is not a quitter and it is going to be a tough fight for AJ. I don’t think that it is going to be easy at all. The mental state that AJ has, is he going to hold up? When he fights in the UK he has a little more oomph in his step.

“But when he fights outside the UK, we don’t get the same fiery person, the playing ground is going to be a little more even in Saudi. I wish all of the luck to Wallin. I want to really be the one to knock out AJ but may the best man win, it is what it is.”

Joshua and Miller were slated to face each other in 2019, but the fight fell apart when Miller tested positive for several banned performance enhancing drugs.