Haye is hoping to prove himself as a heavyweight
David Haye will fight American Monte Barrett in a 10-round heavyweight contest at the O2 Arena on 15 November.
Haye has lined up the 37-year-old after his original opponent, JD Chapman, missed a media launch.
Barrett, 37, has lost two heavyweight world title bouts to WBC champion Hasim Rahman and WBA holder Nikolay Valuev.
"Barrett is pretty much a perfect opponent. He's an exciting heavyweight who always puts up a good fight," said ex-world cruiserweight champion Haye.
"At the same time, though, he's also a dangerous heavyweight who has surprised many other up-and-coming heavyweights.
"Nobody can ever take anything for granted with Barrett. There haven't been many boring Monte Barrett fights and I'm sure he'll be there swinging on 15 November.
"He's been fighting world-class heavyweights and hanging with them for years.
"When I beat Monte better than anybody has before, people will start to realise I'm serious about becoming world heavyweight champion."
Haye has 21 wins from 22 fights with 20 knockouts, while Barrett's professional career consists of 34 victories (20 knockouts) and six defeats.
"Haye's caught my attention with all the talk he's been giving," said Barrett.
"David Haye will be in really deep water coming up to heavyweight, because he's not bringing any power with him - he may bring a little speed - but he's going to get annihilated when he fights me because I'm a seasoned guy who's hungry.
"I'm not just hungry - I'm desperate. And when you're desperate you do desperate things.
"I mean, I don't wash up when I'm in training camp - I don't change my clothes. All I do is train and fight.
"You ask my trainer and he'll tell you - before the Fields fight, I was hitting the wall. I was ready to go.
He added: "I love the UK. Also, I've got to redeem myself. The last time I was in the UK I lost to (Wladimir) Klitschko.
"You could say I'm not that great against big guys, but Haye isn't a big guy himself. I'll get redemption this time in the UK."