According to Eddie Hearn, the promoter for IBO, IBF, WBA, WBO heavyweight world champion Anthony Joshua (22-0, 21 KOs), their full focus is to secure a unification with WBC king Deontay Wilder (40-0, 39 KOs) for Wembley Stadium on April 13.
Joshua returned to Wembley this past Saturday night, and knocked out WBA mandatory challenger Alexander Povetkin in seven rounds.
Wilder is returning to the ring on December 1, in a world title defense against undefeated lineal champion Tyson Fury.
Hearn reveals that his father, Barry Hearn, will be traveling to the United States in the coming weeks to sit down with Shelly Finkel, who is the co-manager of Wilder.
The two sides had discussed the idea of a fall unification a few months ago, but their discussions fell apart after an agreement failed to be reached on the financial terms.
Hearn admits Dillian Whyte is certainly the backup opponent if a deal with Wilder is not reached. Whyte fought Joshua in a war back in December 2015, with Jsohua getting stunned early and coming back to stop Whyte in seven.
Hearn told Sky Sports: "We have got a couple of months. We have made it quite clear we don't want to wait until December 1 to see what happens. We want to get a deal in place to know before then. My old man is going to sit down with Shelly [Finkel] in early October to try and talk through a deal. We have sent them the signed contract on all the terms that they agreed. They did not reply and they obviously did not send it back either.
"So we just want to know what they want now. They agreed to that before. If they do not agree to that now, then no problem. Let's try and make a deal, subject to you winning in December. The absolute sole focus for us right now is to fight Deontay Wilder for the undisputed title in April.
"Obviously if Fury wins, then he will have a rematch clause with Wilder so they are both out. Then we may step into a WBO mandatory with Dillian Whyte. But the focus is Wilder - 100 percent - and there is no reason why we cannot get a deal in place subject to him winning in December. "