I think Bellew is a live underdog
Haye hasn't fought in over 5 years. I don't count those light sparring sessions he has had as a fight.
Also, at HW Haye has really been smokle and mirrors. Barrett, Bonin,Harrison, Valuev, Ruiz, Chisora, De Mori, Gregarg is about as bad a cv as you are likely to see
His power should be enough to get Bellew out of there but I wouldn't be shocked if Tony pulls it off