Anthony Joshua v Wladimir Klitschko: 'Father Time' has caught up with Ukrainian

Anthony Joshua turned professional in 2013

Briton Anthony Joshua says "Father Time has caught up with Wladimir Klitschko" as the two prepare for Saturday's heavyweight world title bout.

Klitschko, 41, lost his heavyweight title to Tyson Fury in November 2015 - his first defeat in 11 years.

The Ukrainian will fight Joshua for his IBF title and the vacant WBA Super and IBO heavyweight belts at Wembley.

"He has to pass on the baton. I do hear it a lot, he's too old, he's faded," Joshua, 27, told BBC Radio 5 live.

"But then I try and flip it. Even if he is too old, which I think he is, he's in a good place mentally and that's a dangerous fighter.

"Timing is everything and maybe Father Time has caught up with the former champ."

• Hear more from Joshua speaking to BBC Radio 5 live

• Listen to the full 5 live Boxing with Costello and Bunce - Joshua v Klitschko preview

• Wladimir Klitschko: Anthony Joshua will be 'facing Mount Everest' for heavyweight title

Rob McCracken, who has trained Joshua since his days as an amateur, said the Ukrainian's age was a factor in his team accepting the fight.

"I'd be a liar if I said it wasn't the case. I think the last couple of fights he hasn't looked at his best," said McCracken.

"Timing is huge in boxing. Klitschko is coming to the end of his reign as a heavyweight on the planet.

"We are rolling the dice with Anthony in this situation. It's a huge step up in terms of experience and the calibre of the opponent but we think the timing is right."

'He's obsessed and I'm confident'

Joshua retained his IBF heavyweight title with a third-round stoppage of Eric Molina in Manchester in December

In 2014, Joshua visited Klitschko's training camp to help the Ukrainian prepare for his bout with Bulgarian Kubrat Pulev, which he won.

And Joshua, unbeaten in 18 fights since turning professional in 2013, believes he has come a long way since the two last met three years ago.

"I am a completely different person now. I'm at a place now where he's obsessed with beating me and I'm confident," he said.

"I'm not a gym fighter. If I'm depending on his age and he's depending on the sparring from years ago then he will definitely get it wrong.

"He's got to come across a young lion who studies the game.

"Whatever type of fight he wants to fight, if it goes down the route of us two swinging until the cows come home, I don't think I will back out.

"My obligation first and foremost is to make him look like a novice."