The bookmakers have been unable to separate the athletes ahead of the rematch, but Hearn insists that 'The Bomber' should be the favourite.
"Bellew was a huge underdog first time, now the bookies can't split them. I'm not sure I've been more confident going into a 50-50 fight," BBC Sport quotes him as saying.
"It's a wonderful career Haye has had but I believe it ends on Saturday night and Tony Bellew goes on to get the credit he deserves."
Bellew saw off an injury-stricken Haye in the original contest and a second defeat for the latter could prompt him to retire.