Step#1- Don't buy into your own rumors that you have a " granite chin". because you certainly don't have a granite face. step#2- Do not catch punches with your face. step#3- Learn some head movement. step#4- Be cautious avoid damage by applying steps 1-3 step#5- take it to deep water and do what you do. it will not be easy and personally I think he should just wash his hands of it and move on to the next.
Start off fast like you mean business, constant up and down attacks, mixing up shots to keep Sheldon guessing. Move to your left to stay away from that down sniper shot. Make a concerted effort to go to the body. Play the long game. He does the above and he gives himself the best chance to win.
The same way he beat Dubois, control the range early and step into him later on. He must move to his left more and invest in his body shots.
Head movement will only get him so far. He's better off just making a commitment to circling the correct way (his left) to take the sting off Zhang's straight and letting his workrate do the rest.
Martin Bakole is closer to Foreman than Joyce is. Joyce is more like a weird Antonio Margarito / Max Baer combo with added molasses.