He's up against a 36 year old man who has fought for about 400 seconds since the summer of 2012.
Haye hasn't been in any kind of fight since a major operation so we don't know how his body (shoulders?) will hold up after a few rounds of action.
Since Haye beat Chisora Bellew has fought THIRTEEN times, losing only to Adonis Stephenson and beating some decent fighters along the way including stopping the very highly rated Makabu - who had beaten his previous 19 opponents, stopping 18 of them - as well as Flores who had never been stopped.
Bellew is punching harder than ever. And boxing smarter than ever. He's been improving while Haye's been...well doing what Haye does.
And here's the clincher. The last time Haye fought a Light Heavyweight turned Cruiserweight from the North West of England was against Carl Thompson
I don't seriously expect Bellew to win but I don't think it's the complete mismatch most on here appear to. I can see a decent battle for a few rounds til Haye's heavier weight counts - similar to Brook GGG. Actually that's not a good example is it