Tyson Fury admits he is going in to Saturday's fight against Alexander Ustinov at Manchester's Phones 4U Arena knowing virtually nothing about his opponent - but says anything is better than letting down his fans.
Ustinov is a last-minute replacement for Dereck Chisora, after the Londoner broke his thumb while sparring with the Belarusian on Monday.
The pair were able to get the measure of each other for the first time at the weigh in on Friday, with Fury weighing in at 18 stones and five ounces - exactly two stones fewer than his stand-in opponent.
Fury said: "I'm buzzing to be in a home town fight. I didn't want to let anyone down, that's why I took Ustinov on.
"I'm very excited and I'm in great shape but it is what it is. I'm going in blind, I don't know what to expect.
"I've had no preparation, no sparring, I've had nothing for this fight. No game plan, so we're going to see on the night how I can adapt to a different man."
Chisora's withdrawal left promoter Frank Warren with a race against time to find a credible opponent for Fury.
After managing to catch Ustinov hours before he left for the airport, he is confident fight fans in Manchester will be excited to see a match up which could go either way
"Tyson's fight against Dereck was obviously a very competitive fight and a fight that we were all waiting to see but it wasn't to be," said Warren.
"Ustinov is a big puncher, a totally different opponent to what Tyson's been training for when you look at the fact Dereck's only 6ft 1ins, suddenly he's fighting a guy that's virtually the same height - in fact they're the two biggest heavyweights I've ever promoted.
"It's a tough job for Tyson, mentally to readjust your whole game plan. On the night I think suddenly the bell's going to go and we're going to see a little bit of a war here and Tyson can't afford to lose."
Standing at 6ft 8 ins tall, the man dubbed 'The Beast from the East' started life as a kick boxer before moving in to boxing and has an impressive record thus far, losing just one of his 30 professional fights, to Bulgarian Kubrat Pulev.
He admits he was disappointed to be involved in the sparring incident which ruled Chisora out of the fight, but says he jumped at the chance to replace him in the ring when Warren called his team.
He said: "I was really sorry for what happened to Dereck but these things happen in sport.
"It wasn't quite obvious at first how bad it was. We stopped because of Dereck's reaction and 10 minutes later his trainer came back out and that's when I realised something bad had happened.
"You might say I have a hard head, maybe he has a hard punch."
"I think we are on the same level because he was preparing to face someone smaller and so was I.
"I feel prepared, so it is a perfect opportunity especially because I have always looked forward to fighting in England because boxing came from here.
"Now that I'm here I know that it will be very tough because everyone in the arena will be supporting Tyson."