Eddie Hearn says Anthony Joshua is waiting on whether Wladimir Klitschko will ask for a rematch.
The unbeaten British boxer stunned the world with an 11th round knockdown in front of 90,000 fans in Wembley.
Joshua also has the option to face mandatory challenger Kubrat Pulev, but Hearn will prefer a Klitschko rematch.
“We have a mandatory challenger in Kubrat Pulev for the IBF. We have a situation with Wladimir Klitschko where we would like to make that fight again,” Hearn told Sky Sports.
“Fans and broadcasters would like to do that fight again and Wladimir is currently on holiday for two weeks and he will make a decision on his return.
“If that’s a fight that Wladimir wants, I feel like that will be next for Anthony Joshua.”
“Of course there are other big fights outside of his mandatories,” said Hearn. “The two champions. Joseph Parker, we just saw him defend his world title, Deontay Wilder.
“We have got a six, eight, 10-year plan with Anthony Joshua, so people are talking about all these super fights now. We want them, but we have also got to realise there is a long way to go.
“We have to box off these mandatories and the aim is to become the undisputed heavyweight champion of the world, to collect all those belts.
“To do it we are going to have to be very smart, we’re going to have to do a lot of manoeuvring around and he is going to have to do a lot of winning in the ring.”
The IBF expect to make a decision about Joshua’s mandatory obligations by early next week.