Deontay Wilder has been told to hang up his gloves if he is not prepared to face Tyson Fury for a third time.
Wilder clung on to his world title in his first meeting with Fury when the rivals fought to a draw in 2018.
But 14 months later the American was dumped on the canvas and stopped in the seventh round.
Wilder quickly activated his rematch clause and the trilogy clash was pencilled in for first July 18 and the October 3.
But the coronavirus crisis has pushed the fight back until December 18 - although that date is not yet set in stone.
And promoter Eddie Hearn - who represents Anthony Joshua - has told Wilder he must save face by following through with his revenge mission.
He told iFL TV: "I don’t believe Deontay Wilder is going to let that fight go. If he lets that fight go, he’ll never get another shot at a world title until he’s mandatory.
"If [he] doesn’t take that rematch, he should retire from boxing. What’s the point? You’ve been a world heavyweight champion, and now you’ve lost and your bums gone.
"You’ve bottled the rematch, and he won’t. He’s got more about him than that but he’s worryingly quiet, isn’t he?"
Hearn hopes to stage an undisputed fight between Joshua and Fury next year, assuming the rivals come through their interim bouts.
Joshua is due to take on Kubrat Pulev a week before Fury faces Wilder and victories for both could see them clash next spring.
