First, we looked tired. Two games since Chelsea last played does that to you. Secondly, a very different game if Luiz gets the obvious red card. Atkinson strikes again.
As for the players.
Blind - poor game, but hung out to dry by Smalling. So many times he was expecting Smalling to be coming across and he wasn't there. He plays that way as CB but maybe he shouldn't be expecting Smalling to play the same way, although Smalling should communicate better as the CB.
Smalling - shocking. At fault for all four goals. As bad a performance as I've seen in years from a Manchester United player. No positioning, leaden footed, dithering on decisions, shirking responsibility, and more. Should be benched for a long time after that.
Herrera - he's our man for that keep ball role. Left to run the midfield on his own but he bailed us out of our own mistakes multiple times and almost never gave the ball away.
Fellaini - junk. Lost the ball nearly every time it came to him and a big part of the reason we couldn't string two passes together in the first half. Waste of a position and he should be phased out of the club.
Pogba - on one hand he was taking no risks, playing nothing forward at all. On the other hand, Ibrahimovic was nowhere to be seen and the wingers were so deep he had no-one ahead to pass to. Needs to do better but he can't create if there's no-one moving to receive.
Ibrahimovic - hes starting to look like he can't keep up. He's making no runs, is getting beaten to all loose balls and is struggling to hold it up. More than anything I think he needs a rest, but Rashford should take his spot for a game or two.
I want to see next:
DDG
Valencia - Bailly - Blind - Shaw
Mata/Carrick - Herrera - Pogba
Miki/Lingard - Rashford - Martial