Deontay Wilder told Tyson Fury "we know your secrets" ahead of their rematch as the heavyweight world champion aims to expose a cut the challenger sustained in his last fight.
The highly-anticipated second bout appeared to be in danger of being delayed when Fury suffered a deep cut during the third round of his points win over Otto Wallin in September.
Fury later claimed he needed 40 stitches for the wound and it was noted by Wilder that he wore sunglasses during Wednesday's news conference.
The Briton's cutman Jacob 'Stitch' Duran has since revealed Fury has had mesh web inserted into the soft tissue above his eye but stressed "it won't be an issue" in Las Vegas on Saturday.
However, Wilder believes the problem is more serious than Fury or his camp are letting on.
"That's definitely something that I'm targeting," he said.
"When a fighter has a wound that, we feel, is not all the way healed - no matter what he says - because as a fighter being in here, as a veteran being in the game, you see so many different things and you can acknowledge a lot of things and you know.
"It's like him coming to the press conference, he changed up something. He wore a hood and he wore glasses. He's covering up something. Fury, we know your secrets. We know what's going on.
"That was just one of those things where he was just trying to cover up.
"He didn't want me to see how severe the cut was. You hear all the rumours as well that he didn't allow his sparring partners to hit him in the face, they just did body sparring and different things like that.
"That just shows a strong indication that something happened in that camp, something happened with his eye.
"Credit to him, he's a warrior, he's still coming, he's still trying to cover it up and come Saturday night is going to be ready to show up and present himself as, what he calls himself, the lineal champion."
Wilder will be denied the chance to have a closer inspection of Fury's eye on Friday as the traditional pre-fight face-off at the weigh-in has been cancelled after the pair confronted each other on stage on Wednesday.
WBC champion Wilder, whose record stands at 42 wins and one draw from his 43 fights, will be hoping to make the 11th successful defence of his title.
The only time he did not emerge victorious was in the original meeting with Fury back in December which ended in a contentious draw.
Of Fury's 30 fights, that was the only bout he has not won too.
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