Joshua is due to put his world heavyweight titles on the line against IBF mandatory challenger Kubrat Pulev at Tottenham Hotspur Stadium on June 20.
Hearn, the Brit's promoter, knows that is unlikely to go ahead due to the coronavirus pandemic, given there is no knowing when sport will resume and Spurs still have a Premier League season to finish.
Fury and Wilder were due to do battle for a third time in July, but the WBC champion's co-promoter, Bob Arum, said the trilogy fight could be put back to October.
Hearn does not feel Joshua would have an issue stepping straight into a titanic showdown in search of a sweep of the titles at the end of the year if there is a drastic change of plan.
He told BBC Radio 5 Live: "Right now our plan is to fight Pulev in June or July then fight Fury or whoever holds the WBC belt at the time.
"If the Pulev fight can't take place we may end up seeing that fight [against Fury] happen later this year.
"It wouldn't be ideal for AJ boxing in December to have been out for a whole year going into a fight like that but I don't think he would have a problem with it."
Joshua won a rematch with Andy Ruiz Jr. in Saudi Arabia last December to regain his WBA, IBF and WBO straps.
Photo Getty Images Caption: World heavyweight champion Anthony Joshua and Eddie Hearn