Hearn, who is Haye's co-promoter of the heavyweight showdown in London, told Standard Sport: "I will make no bones about it - I want Tony to knock him spark out and finish him."
Former WBA world champion Haye has been involved in a bitter war of words and insults with Liverpudlian Bellew.
But Haye has also been feuding with Hearn, even though they are partners in staging the sell-out grudge match at the 02 Arena.
Hearn said: "I think David came back into boxing just to make a few quid.
"That is his number one priority. As you approach the back end of your career, the money takes over. But I hope Tony Bellew derails him. And if that happens, Haye's career is over.
"David is a great self-promoter. But when you talk about desire and will to win, does he want the money and the limelight or does he want the achievements and the glory of victory?
"I have to say it’s the first option. I just don't believe he has returned to try to recapture the heavyweight title.
"I don’t know whether he needed the money but he certainly saw the opportunity to make some.
"And he saw the boxing game and the heavyweight division being revived. That is why he returned.
"There is nothing wrong with that. Boxing is the toughest sport in the world. Fighters should earn as much as they can from it.
"But I just don't believe him when he says he has a hunger to become heavyweight champion again. What he has is a hunger for money.
"Now he's got to win this fight to keep the pay-days coming."
Bellew, 34, is stepping up from his position as WBC world cruiserweight champion to take on 36-year-old Haye - who himself climbed from cruiserweight to reign as WBA heavyweight champion between 2009 and 2011.
Bermondsey's Haye had two low-key comeback fights last year after a three-and-half year spell in retirement following a serious shoulder injury.
Both boxers have been warned to keep their cool by the British Boxing Board of Control during a heated build-up to the fight.
They first clashed at a press conference last November when Haye also lashed out verbally at Hearn, saying: "He promotes himself, not his fighters."
Hearn added: "When this is over and David's cheque arrives, the one thing he should be doing is thanking me.
"He is definitely in good shape for this. And he is one of the best British boxers we have had who has achieved so much as a heavyweight and a cruiserweight.
"He has tremendous speed and power. We know that. But the real issue is that he hasn't been in a real fight or been hit on the chin for five years.
"He definitely doesn’t have the drive and hunger he had before.
"I don’t care what he says - he just doesn't have it. It’s impossible.
"Regardless of whether he thinks he has still got it, there is no way he is the same fighter he was five years ago.
"He has a bad injury and he has been inactive.
"He is still an excellent fighter. But this is a case of the unknown. It is a big risk for him going into this fight.
"Tony knocks out cruiserweights and Haye is a pumped-up cruiserweight.
"Haye is going to have to be some big piece of the fighter he was to win this. A shot, finished David Haye does not win this fight.
"And I believe - and want more than anything - for Tony to win. He is right up against it. But I believe he can do it."