Sooner or later Stephens, Gross and Propper are going to need a rest as they do as much running as anyone and have played every league game. But with Sidwell out and Kayal short of match fitness, we don't have too many options, do we?
Brown for Gross is the obvious change, but it will be a risk...
I'd actually play Knockaert at Old Trafford, where the surroundings might lift him. But start Solly against Palace - he'll appreciate what it means without getting carried away, as AK might.