I know that Whyte gets a lot of hate but I certainly wouldn't count him out. Whyte did beat Parker and managed to spark Chisora out in the rematch. It's not like Kabayel is some massive puncher I would favor Kabayel to win on points but would not be shocked if Whyte pulled it off.
When and where are the biggest factors that decide whether Whyte is in the mix or not for me. A fight in the UK with friendly British officiating to be kind gives Whyte leeway to turn this into a street fight; blind murder in the clinch with rabbit punching and leaning his body weight on the neck, hanging onto the ropes. Throw in a casual headbutt for good measure and he may get a decision. Basically his Parker fight - probably his best win, which he was very close to losing at the death. Neutral venue - nowhere near as clearcut. He is tailor made for Kabayel who is a far superior boxer anyway and Whyte doesn't have the movement for him. For me Kabayel by a wide decision, possibly even a KO.
Whyte had a good run in his prime but he'd be open to those bodyshots all day long and would be broken down late like in the Parker fight (almost).
TBF to Whyte he has (had?) bundles of heart and would always go down swinging. Unfortunately for him Kabayel would beat the fight and heart out of him with his vicious body attack, en route to a stoppage win.