Given the choice, I'd rather have Mangala than Evans so it's not all bad. Didn't look too bad in pre-season and I'd start him against the rags alongside Vinny to combat Lukaku.
I think he could be very valuable in that situation. We are guaranteed to make one or two mistakes that results in counter attacks, and against United that could be absolutely fatal. I don't want to see Lukaku, Martial, Mkhitaryan and Rashford tearing up the pitch towards a lonely Ederson. Thing is Pep is such a fanatic that he will set us up in a way that leaves us vulnerable to that.