Wladimir Klitschko revealed being the underdog against Anthony Joshua is "beyond motivation" for the former heavyweight champion and the veteran is using the words of JF Kennedy to inspire him at Wembley this weekend.

Joshua is a strong favourite to retain his IBF world heavyweight title with the backing of a partisan crowd in his homeland on Saturday.

Klitschko is accustomed to having the weight of expectation on his shoulders, so the 41-year-old is revelling in not feeling such pressure to win in London.

"Can you believe this? I'm actually an underdog," he told Sky Sports' Behind The Ropes.

"I actually talk to myself sometimes and I say 'Wlad, you're an underdog. It's great, it's beyond motivation and I just only can win, I can't lose, I only can win'.

"Originally this phrase, I've heard from JF Kennedy, when the first human team went to the moon and he said this one line – failure is not an option – so you're going to get to the moon and you're going to come back, which happened.

"So failure was not an option and in a certain way I adjusted it to my mentality and to my team slogan, that 'failure is not an option'.

"It's really something that you've got to do what you've got to do. There is no other option – you have to do it."