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"I don't underestimate any opponent", Joshua said at a pre-fight press conference at the London headquarters of United Kingdom satellite broadcaster Sky on Thursday.
"This stick is going to be integrated in my robe which I'm going to wear on Saturday night". The 27-year-old said: 'Well, I don't know how to answer that'.
"It is not about mind games, this is my game that I just wanted to bring it".
Wladimir Klitschko's recorded a video prediction of Sunday's title fight against Anthony Joshua on a USB drive and sealed it in his robe to be sold off to charity. In this insane world - and I call it insane because we've seen actions in the past, bad events - a violent sport such as boxing shows that, through sports, you can clarify each other's differences under the rules and then continue your life. I tell them, 'Guys, I want to do good, but I can't help you.' They say, 'Why?
The pair will meet in front of an expected 90,000 fans, a post-war record for a United Kingdom boxing match.
"I am the victor, already before the event".
"It took me back to the time when I fought Johnson", he said.
Joshua, who has had 18 professional fights compared to Klitschko's 68, responded: "If I couldn't box I wouldn't be here". Dre: Thank you so much man, just trying to be inspirational as much as I can you know AJ: You still remember where you come from Dre: Oh yeah, absolutely AJ: It's insane how far you've come Dre: Good luck to you man this Saturday AJ: I was listening to Dre - Let Me Ride, I was listening to that yesterday, and some BG knockout, you still bang all those tunes man. That's got me here.
He said: "I know Joshua is a very good fighter who has great skills, he has great fight record but I have to say Joshua has never fought against an opponent as high quality as Wladimir".
London-born Joshua, like Klitschko standing at 1.98 metres, described this weekend's fight as a "stepping stone to greatness".
Klitschko - who shouted "fake news" at one reporter when asked about a rumoured eye-socket injury - is bidding to regain two of the three major titles he lost to Tyson Fury in his last outing in 2015.
He insisted Thursday he was enjoying being challenger again as he attempts to become a three-time world heavyweight champion, following in the footsteps of his elder brother Vitali, Lewis, Evander Holyfield and Ali.
Joshua grinned back and said: 'This is not complicated for me. It will not be. But Joshua never have (an) opponent so high in quality as Wladimir.
Britain's Joshua, making his third defence of the IBF title he won against American Charles Martin last April, looked nervous at Sky TV headquarters where renowned American MC Michael Buffer introduced the fighters.