George Groves' world title shot looks likely to be pushed back to the next Floyd Mayweather bill.
The London super-middleweight's WBC challenge against Badou Jack was supposed to take place in Las Vegas on August 22.
But it could be pushed back three weeks to be part of the undercard for Mayweather's expected showdown with Andre Berto on September 12.
Groves' third shot at a world title will be screened in America on Showtime, who have confirmed it will not take place on the original date.
"Showtime doesn’t have a live boxing event on August 22," said Chris DeBlastio, Showtime’s vice president of sports communications.
"We had contemplated doing it (that date), but it didn't materialise."
WBC champion Jack (19-1-KO12) is part of Mayweather Promotions who have the option of including his defence against Groves (21-2-KO16) as part of the September date, which will be screened free-to-air in America.