This news comes days after the WBA ordered ‘AJ’ to agree to face their number one Luis Ortiz within 30 days.
As WBN stated earlier this week, the WBA are working with the IBF in a bid to come to an arrangement so Joshua can keep both titles.
Hearn is hopeful Joshua can clear up both stipulated bouts before embarking on a massive unfication with Deontay Wilder in the summer of 2018.
“On we go plotting the next moves for Anthony Joshua,” said Hearn in his latest Daily Mail column.
“We are making good progress and we know the fourth defence of his IBF world title and the first defence of his WBA crown will be against the IBF mandatory challenger Kubrat Pulev.
“As for the dates, we are still looking at the two nights we had in mind when we were planning the Wladimir Klitschko fight – we had the two options of Cardiff on October 28 and Las Vegas on November 11. Those still remain, although Cardiff is now the front runner.
“It’s going to be a tough job keeping the governing bodies happy with upcoming mandatories but AJ wants to hold all the belts and handle his mandatories in the process.
“The three-fight wishlist reads Pulev, WBA mandatory Luis Ortiz and then another unification fight with America’s WBC champion Deontay Wilder.
“That is the plan and now we want to make it happen,” he added.
Pulev on the October/November date mentioned before Ortiz in February or March would lead Joshua nicely into a mega-fight with Wilder, potentially in June or July at Wembley if successful.