Frank Warren admits Dereck Chisora's credibility is at stake when he meets unbeaten American Malik Scott at Wembley Arena on Saturday

Chisora enters his 21st fight having lost four of his last six contests, leaving him at a pivotal moment of a controversial career that threatens to pass unfulfilled.

Even allowing for the fact he has lost only to Vitali Klitschko, David Haye and Tyson Fury - the latter while he was out of shape - and dropped a highly-dubious decision to Robert Helenius, Warren knows a fifth defeat would be damaging.

"Although you look at the calibre of fighter Dereck has lost to and the poor decision he got, to be in the mix you must win," the promoter said.

"If he loses we have to find somebody else for him to fight, someone he can beat and someone against whom he can get some credibility back.

"This fight is about credibility for Dereck, about showing that he belongs with the elite and is capable of doing it when he gets into good physical condition.

"He certainly can't afford a loss now, he has to be win, win, win all the way.

"Dereck does not complain, even when he's robbed he doesn't sulk. I have a lot of time for him."

Chisora and Scott recently traded insults during an expletive-ridden telephone conference call, but only mutual respect was evident today.

Having complimented each other throughout the head to head press conference in central London, Scott presented his rival with a cigar that he proposed they share after the fight.

The bad behaviour and unpredictability that earned Chisora his notoriety have been replaced by a calmer figure that has benefited from lessons in anger management.

"I'm in a good place right now," the 29-year-old from Finchley said.

"When I lost my fight with David Haye one of my rivals said to me 'you've done it all. You've lost four fights, now the rest will be easy because you don't have that worry about losing in your head'.

"I thought he was talking a load of rubbish when he told me that, but well and truly it is easier for me now.

"I'm in great shape and on Saturday there will be fireworks. Just wait and see. I'm looking forward to this fight more than any other."

When asked about the good-natured press conference, Chisora responded: "I'm just scared that I'll be fined by the board (British Boxing Board of Control), so I'm keeping quiet! For now I'm calm, but who knows what will happen?"

Malik has drawn one of his 36 fights, but his record is short on quality opponents. Despite possessing only a 33% knockout rate, he intends meeting Chisora head-on.

"Dereck won't have to come looking for me, this isn't a dance contest and I'm not Fred Astaire. I don't have the energy I had as a 20-year-old to bounce around the ring," he said.

"Absolutely Dereck is the most dangerous opponent I've faced, he's coming to hurt me."