The Alabama fighter seemed to be on a collision course with Joshua when the pair held all four heavyweight belts in 2018.
But the fight was put on hold after Wilder seemed to reject an offer, instead deciding to fight Tyson Fury on his return to the sport.
Fury dominated Wilder in February 2020 with a brilliant display, taking his WBC belt in the process.
The two-fight deal could be worth up to £200million and will be the biggest event in British boxing history.
Hearn is currently locked in negotiations with Fury's promoter Frank Warren to get the contract over the line.
When asked about a potential fight between Wilder and Joshua, Hearn told Sky Sports: "If it's the right fight for AJ, not stylistically, but if it's the right commercial fight.
"Listen, Deontay Wilder knows he turned down the deal of a lifetime to fight Anthony Joshua, but he made his bed and respect to him.
"I want to see him [Joshua] back in the ring.
"All we're focusing on is the Tyson Fury fight, and anything else happens in 2022, because those two fights will be our plan for 2021."
It looks like Joshua could face the 'Bronze Bomber' next year, should he overcome Fury and become the undisputed champion first.
The winner of Fury v Joshua will also have to take on former cruiserweight king Oleksandr Usyk.
The Ukrainian is demanding a title shot after beating Dereck Chisora in his first major heavyweight bout.