Lennox Lewis thinks Tyson Fury will have to “to do a lot more” to beat Oleksandr Usyk in their heavyweight rematch on 21 December.

Fury, 36, will be seeking revenge against unified champion Usyk having lost their first encounter in May by split decision.

Lewis, a former undisputed heavyweight champion, is backing Fury to beat his rival if he learns from his mistakes in the first fight.

“I think Fury learnt what he needs to do next time because he didn’t do enough. He needs to do a lot more. I like him a bit heavier for his fights and not moving around as much,” Lewis told the 5 Live Boxing with Steve Bunce podcast.

“He has to conquer his own self first. He’s been through these things before so I think he can do it because he knows what to do.

“He’s been at lows before and at highs before. He’s down here right now, he knows how to get back up here. He just needs to put in the work.”

Before 37-year-old Usyk defeated Fury, British fighter Lewis was the last man to become reigning undisputed heavyweight champion in 1999.

The Briton defeated Evander Holyfield for the title, winning in a rematch after their draw earlier that year.

Lewis competed in three key rematches in his career. He twice came back to win after losing a first bout, once to Hasim Rahman in 2001 and once to Oliver McCall, who beat him in 1994 before folding to defeat in 1997.

Now 59, Lewis says he was driven by “revenge” in those contests and says Fury will be going through the same thing after the first loss of his career.

“Every day I woke up training for this person, ready for this person, thinking about them the whole day. I took it real serious,” Lewis said.

“Wake up every day to their picture. Stick it on the wall. And be thinking about them all the time. It’s a mental war you’re going in against.”