Pulev might rock him if he can play the guitar and knows "Smoke on the Water". Otherwise probably not. I'm not writing him off entirely because he's clearly got skills and size, but the Wlad loss put a giant dent in his confidence and he's not looked the same since.
Pulev looked quite tough and mean with his neanderthal looking head and brow so he should win the prefight ring stare down when the ref gives his instructions but that will probably be as good as it will get for him on fight night.
It's heavyweight boxing, men that size smashing each in the face can result in any fighter getting rocked, dropped or knocked out. Joshua hasn't displayed a rock solid chin and Pulev can dig a little bit, it's possible and like we all know anything can happen in boxing. All that said I expect Joshua to knock the snot out of Pulev.
In fairness to Parker he has fought everyone he has had to including his mandatory.. Wilder has also being doing what he has been told by the WBC and also has to fight his mandatory now the WBC have found someone they are comfortable he can beat...