Former WBO heavyweight champion Joseph Parker is more than ready to begin his training camp for a potential fight with Derek Chisora.

Parker's manager and co-promoter David Higgins is waiting to receive a formal offer for the fight.

The rematch between Joshua and Ruiz is slated to take place in Saudi Arabia on December 7.

But the fight over the rematch location is still ongoing, as Ruiz is standing firm with his rejection to accept the scenario of Saudi Arabia as the rematch location.

Before he can finalize an undercard, Hearn will want to fix all of the issues with the actual main event.

Higgins explained that a backup plan was also presented, with a potential date in October at the O2 Arena in London.

Parker is about to start camp with long-term trainer Kevin Barry in Las Vegas, but they have no confirmation regarding the date or the opponent. Parker and Higgins would love for the opponent to be Chisora.

"If they formally confirm the fight, he'll fly into camp. All we're waiting for is confirmation from the promoter, it's frustrating. Confirmation that it's on and Joe will be straight in camp," Higgins told Sky Sports.

"[A date in October is] what I've been told. We're ready and willing, but we're running out of time."

Hearn mentioned last week that he was very motivated to finalize a deal for the Parker vs. Chisora showdown.

"With Chisora and Parker, there's been lots of talk," Hearn told Sky Sports. "I owe David Haye a call today to try and make that fight."