Klitschko has lost his last two fights

Klitschko is hoping to get back to winning ways on Saturday after his second-round loss to Corrie Sanders and fifth-round stoppage by Lamon Brewster.

"For both of us this is going to be a struggle to survive. It's a big fight for both of us," he said.

"I just want to get in the ring and decide whether to fight again. There are a lot of questions there."

Heavyweight Klitschko was once considered a better fighter than his brother Vitali, who is now the WBC heavyweight champion.

Shock loss for Klitschko

But, after being knocked out by Sanders last year, he was stopped by Brewster in April.

Klitschko's camp later claimed he might have been drugged and asked for an investigation.

But Nevada boxing authorities said all his blood tests at a hospital after the fight had come back negative.

Williamson was knocked out just 97 seconds into his bout against Joe Mesi last September.

But he responded with victories in his last two fights.

"To beat Klitschko on a national stage will do wonders for my career," he said.

The fight tops a card at the new outdoor ring at Caesars Palace in Las Vegas that includes a fight between Jeff Lacy and Syd Vanderpool for the vacant IBF super middleweight title.