Promoter Eddie Hearn revealed that Anthony Joshua is looking for another opponent after Tyson Fury was ruled to fight Deontay Wilder again.
Hearn also gave Fury a deadline of the end of this week to resolve his obligations to Wilder and confirm a fight with Joshua.
Joshua may instead face Usyk and then reschedule a fight with Fury to December.
Fury had previously confirmed that he would face IBF, WBA and WBO titleholder Joshua on August 14 in Saudi Arabia in the most anticipated fight in the sport, but 24 hours later a court of arbitration ruled that he must meet Wilder again by September 15.
Asked if he was now looking at a different opponent for Joshua, Hearn told Matchroom: “Absolutely. I had been focusing on Plan A. The only fight was Fury and we hope it can still take place.
“The game changed – we have to have a Plan B in place, and probably a Plan C.
“We have different options. The one that springs to mind is Usyk.
“If Team Fury don’t get their act together by the end of this week then we will have no option but to look for an alternative fight.”
