I would have said Danilo or Delph... I understand why some are saying Delph but I actually think we have a better team balance(between attack and defence) with Delph at left back over Danilo, so Danilo as DM.
Failing that though since Delph is suspended and Zinchenko would be too much of a risk defensively(at left back) against Arsenal and Chelsea, I wouldn't mind seeing Stones there or Laporte. Both of them have the engine, ball control and the passing that lend well to the role... positionally is another matter, I can't recall I've seen either of them played out of position but if anyone can prepare a player for it, it's Pep. They both seem to have good footballing brains with good positional awareness on a good day, I haven't seen a lot of Laporte yet but it was clear from his first City game he has the edge in his long range passing, so maybe I'd lean towards him.
KDB would be a good shout if he isn't asked to do the defending job Dinho sometimes has to do against tougher opposition, I wouldn't play him there against Arsenal or Chelsea personally(same with Gundo or Zinchenko), in case they are on it.