Challenger Jean-Marc Mormeck opened his war of words with Wladimir Klitschko on Wednesday by insisting he will smash the world heavyweight champion's “glass jaw” on Saturday night.

“Klitschko has something that I want and I need to smash his face in order to get it,” the 39-year-old Frenchman told German television RTL.

“I know that he is not happy getting hit.

“I've already said it and mean it - he has a glass jaw.”

Klitschko is bidding for the 50th knock-out of his career in Dusseldorf when the pair meet with the champion's IBF, IBO, WBO and WBA world titles on the line and was unimpressed by Mormeck's words.

“I'm going to try to protect my glass chin,” he said wryly. “Best of all by looking at him knocked out.”

Klitschko has not been beaten since 2004 and the pair held a public workout on Wednesday in front of around 400 spectators in Dusseldorf.

The pair were scheduled to meet last December, but kidney stones forced Klitschko, 35, to postpone the fight which will be the 60th of his career.

Mormeck is four years older and 17cms shorter than the Ukrainian, but Klitschko says he will not underestimate his opponent who faces only his fourth heavyweight bout after stepping up from cruiserweight two years ago.

“He's in top form and will move around the ring a lot,” said Klitschko.

“He's not as laidback as he looks.”

Meanwhile, Klitschko's management has won a small victory as a Hamburg court has ordered a preliminary injunction against German boxer Marco Huck repeating his comments that Dereck Chisora's slap on Vitali Klitschko was staged.

Chisora slapped the WBC champion's face before their fight in Munich on February 18 after which Chisora got in a brawl with ex-champion David Haye in the post-fight press conference.

In a press conference on March 18, Huck said Boente had staged the weigh-in slap by Chisora to boost ticket sales, but he now risks a fine of up to 250,000 euros or up to six months in jail if he repeats those comments.

“The court's decision is the right one. Huck should think twice in the future before he opens his mouth,” Wladimir Klitschko said of the verdict.