Being completely serious, I think he was absolutely immense in those 31 minutes against United. I'm not sure we'd have won the game without him.
This is all from the Guardian match report alone:
67 mins: "[Lingard] plays an excellent crossfield diagonal to Lukaku who approches the right of the box on an angled run. Mangala refuses to let him come in on his left and he takes two strides and bludgeons a right foot shot miles over."
78 mins: Martial plays in Lukaku down the left of the box with a cute pass but the centre-forward is closed down immediately by Mangala who sticks with him and stays close until he loses control. Superb defending again.
84 mins: Brilliant double save from Ederson. Lukaku volleys it through the six-yard box into the keeper's face. He made himself huge then sprang up to block Mata's effort with the rebound from similarly close quarters. Once more Mangala helped by playing close attention to Lukaku.