Wladimir Klitschko has called on Anthony Joshua to win in style when the Briton faces Eric Molina at Manchester Arena on Saturday.
Ukraine's Klitschko is next in line to fight Joshua and insisted he wants to test himself against the very best when he meets IBF heavyweight champion Joshua in the spring.
Joshua is a clear favourite for Saturday's bout with American Molina and is expected to record the 18th consecutive knockout of his undefeated career, but Klitschko warned he wanted to see more than a run-of-the-mill victory.
"The better Joshua performs, the better it is, because I believe Joshua is right now one of the best men in the heavyweight division," Klitschko told Sky Sports.
"The better he performs, the better it is for the fans and also for myself, because I definitely want to fight the better man to get my titles back."
Former WBA, IBF and WBO champion Klitschko surrendered his belts to Britain's Tyson Fury last year in a shocking defeat and was denied the chance to reclaim them when Fury pulled out of a proposed rematch in October.
Klitschko will be 41 when he faces Joshua next year but heavyweight boxing's elder statesman insisted he has no intention of retiring after the shot at his former sparring partner, who is 13 years his junior.
"Retire? That has not crossed my mind," Klitschko told the Daily Mail. "No-one else will ever have the right to tell me when to end my career.
"Having been champion for so long I did not expect to lose the titles. Now my view is altered. My motivation is different now -- to regain my titles -- and therefore even stronger."
Klitschko added in his Sky Sports interview: "I think [Joshua's] got even better since we sparred because he definitely gained more experience. Even in sparring I could see the talent and obviously he was green and not as much experienced when we fought.