Deontay Wilder and Tyson Fury will be prevented from taking part in the traditional eve-of-fight face-off at Friday's weigh-in for their heavyweight title battle in Las Vegas.
Ahead of the MGM Grand clash, promoters for both boxers have backed a decision to call off the familiar confrontation, amid concerns it could turn nasty.
A news conference on Wednesday descended into rancour as Wilder and Fury shoved each other before being separated.
The Nevada State Athletic Commission (NSAC), which regulates fights in Las Vegas, decided that moment was a clear sign Wilder and Fury should not risk further altercations before getting into the ring.
Speaking to ESPN, NSAC executive director Bob Bennett said: "The reason the decision was made, on behalf of the commission, is because the press conference spoke for itself.
"The actions of the two fighters pushing each other, which was not staged, is not indicative of the image of our sport as a major league sport, thus having a face-off is not in the best interest in the health and safety of the fighters, the public and the event.
"And, quite frankly, that image, where you have two professional athletes pushing each other where somebody could get hurt, is not keeping with the image of a major league sport and we're a major league sport."
Bennett said he told promoters Tom Brown and Bob Arum of the decision and neither man opposed the move.
Arum told ESPN: "If this fight depends on a face-off to sell it, we have not done our job."
However, Frank Warren, who co-promotes Fury with Arum, told metro.co.uk: "It's a stupid decision, the face-off is traditional."
The fight is a rematch after a thrilling draw in December 2018, with Wilder's WBC belt on the line.