Heavyweight contender Tyson Fury knows that a win against Christian Hammer on Saturday at the O2 Arena in London will punch his ticket to a world championship shot against the winner of the April 25 fight between champion Wladimir Klitschko and Bryant Jennings.

Although Fury is already the mandatory challenger for the winner of the bout, he is risking that position against Hammer.

There’s considerable pressure already, given the stakes, but Thursday, Fury (23-0, 17 KOs) raised them even more. He said if he loses he should retire -- although he is not expected to lose and, even if he did, few would expect him to keep actually do it.

“If I can’t beat Christian Hammer, I’m going nowhere and may as well retire,” Fury said. “If I can’t knock him out with one clean punch, then something’s seriously wrong. I’m on a mission to become world heavyweight champion.”

Hammer (17-3, 10 KOs), who has won 10 fights in a row, said he is confident he can make Fury think hard about his future by beating him.

“I respect him for risking his position, but he won’t get a chance to beat me,” Hammer said. “I’m also risking my position to take this fight and to come over here and fight him. I’ve been waiting a long time for this fight and I’ll not waste it.”

Promoter Frank Warren said Fury asked for a solid opponent before challenging for the world title.

“This is a significant fight for Tyson, and he can’t afford to lose because the winner of this fight will definitely get a shot against Wladimir Klitschko after he fights Bryant Jennings in New York,” Warren said. “Tyson has to come through against Hammer. He asked for a fighter in top 10 [of a sanctioning body] and Hammer is at No. 3. That says a lot about him that he wants to keep busy for Klitschko.”