Even if Ziyech was fully fit I wouldnt have him start his first match against MU. Especially how disjointed he has looked in his few subs so far. He needs to be eased in.
I honestly would rather see a 4-3-3 here. Kova,Kante, Jorginho in midfield. Puli,Werner, and one of CHO/Mount in the front 3. Big tie subs of Ziyech and Havertz if we feel they are there for the taking in the second half.