Former WBC heavyweight champion Vitali Klitschko is urging Anthony Joshua to stay on course for a rematch with Oleksandr Usyk.

Klitschko was ringside last September at Tottenham Hotspur Stadium, to watch his Ukrainian countryman Usyk outbox Joshua over twelve rounds to capture the IBF, WBA, WBO, IBO world titles.

Joshua would then exercise an immediate rematch clause.

On the other hand, there has been a lot of discussion regarding Joshua potentially accepting a step-aside deal, to allow a full division unification between Usyk and WBC champion Tyson Fury.

"It is his decision," Klitschko told Sky News.

"But my personal opinion? If Joshua sidesteps in this moment, when the boxing audience expects a rematch and wants to see Joshua vs Usyk, it would show weakness. Joshua, don't do that please. As fighters, we fight not just for ourselves but for the audience. The audience decides. If the audience wants the fight, it must happen. If Joshua sidesteps, I am not sure that the interest in Joshua would be so big in the future."

There was a moment in time when Vitali and his younger brother, Wladimir Klitschko, dominated the heavyweight division.

Their days are long gone, but Usyk has now brought back the unified crown to Ukraine.

Klitschko looks forward to Uysk's second encounter with Joshua.

"Everyone expects the rematch between Usyk and Joshua. Usyk is so strong or did Joshua make mistakes? Who is stronger? That question interests every boxing fan. Let's receive an answer. That's why this fight must happen. Huge fight. Right now, everybody doubts if Joshua is strong enough to fight Fury. He can give the answer in the Usyk fight," Klitschko said.

"If Joshua beats Usyk there will be huge interest [in Joshua vs Fury]. It will be the main fight of the past 10 years. Joshua is a classic boxer, Fury is unorthodox. Both are punchers, both can decide the fight at any moment. Both are world-class fighters and can knock each other out at any second."