Brandon Gonzales insists his fight with James DeGale is 'already won' after a tough training camp alongside world champion Andre Ward.
The American will face DeGale on Saturday night in a final eliminator for the IBF super-middleweight title, live on Sky Sports Box Office.
At the pre-fight press conference, DeGale suggested his opponent lacks the experience of gruelling battles, pointing to how he had seen him 'die' in 12 round fights.
Gonzales has been sparring with Ward in the build-up to the bout, with both men sharing the same trainer Virgil Hunter, and is confident his sessions with the top man in the division will ensure he is more than ready for DeGale.
"It's a big show a big event, 80,000 in front of Wembley. We're just soaking it all in and we're ready," he said.
"We had an excellent training camp. Me and Virgil Hunter have got an excellent game plan coming into the fight, I'm extremely confident.
"As far as the fight goes, it's already done. We've put the work in, the fight was already won weeks ago in the gym and now I'm going to put on a display of what we've been working on.
"Twelve round distance again, all my trials have been by fire. My first 10-round fight was against a legitimate top 168lb contender, which I don't think James can say he has fought anybody in that division in the top 10.
"I fought numerous gatekeepers who have upset prospects coming up early on in my career and all that has prepared me for this moment.
"Twelve rounds in a fight, we go 13 in the gym, 14 in the gym with the likes of top guys, not only in the pound-for-pound.
"You guys know I sparred with Andre Ward and other top contenders in the gym, so we're prepared for this moment."
The Sacramento man has won ten of his 18 fights inside the distance and warned DeGale that he might not last until the later rounds at Wembley.
"Another thing, it has to go to 12, we have to get to the 12th. I'm expecting James to take me to that 12-round distance," said Gonzales.
"There's a possible chance the fight could end early, you don't know, this is boxing anything can happen."