Anthony Joshua claimed Kubrat Pulev "spoke a lot of rubbish" after the two heavyweights were involved in a heated exchange at Friday's weigh-in.
Joshua came in at 17 stone and two pounds ahead of the defence of his IBF, WBA and WBO titles at Wembley Arena – slightly heavier than when he regained those belts by beating Andy Ruiz Jr in their rematch last December.
Challenger Pulev was two pounds lighter on the scales, though the weights were not the real story as the pair verbally sparred with each other.
The lengthy conversation went on for several minutes on the stage and continued as Joshua stepped away to conduct media duties.
"He spoke a lot of rubbish. That's all it is," the unified champion told Sky Sports, opting not to reveal exactly what was said to spark the situation.
"Many years I've been watching boxing and have seen fighters talk a load of rubbish, then they get smacked up. That's just him doing what fighters do."
He continued: "That doesn't really intimidate me. I would have just cracked him in his jaw there and then, but I've got to do that tomorrow."
Joshua is fighting for the first time on home soil in more than two years. A total of 1,000 fans will be present at the venue, following an easing of restrictions amid the ongoing coronavirus pandemic.
He stopped Alexander Povetkin in the seventh round back in September 2018 at Wembley Stadium and, following the terse back-and-forth discussion with Pulev that kept security busy, made clear he does not expect this bout to go the distance either.
"I know what's he like. He thinks he's a warrior," Joshua said. "I said, 'Don't let the guys you've fought 'gas' you up - you're in against a real one now'.
"We're big boys, we punch heavy. The first man to land, that will be the last man standing."