Bellew admitted after his impressive win that he was unsure whether he would continue boxing, but Hearn insisted earlier this week that he was '100% confident' the Merseysider would return to the ring at some point in 2017.
It has now been announced that Bellew may require surgery on a suspected torn capsule, however, likely ruling him out until the end of August at the earliest.
"The concern is they might have to open up his hand and have an operation," Hearn told Sky Sports News. "He's got to test it out in about three or four weeks. If it's still sore, then they are probably going to have to open the hand up and have some surgery on that.
"If that is the case, he will be out for five months, which doesn't affect things too much. If he fights again - I keep telling him he's going to fight again but you never know - probably October, November, December anyway."
Haye is also recovering from a ruptured Achilles injury sustained in the sixth round of the fight.