Lack of a real midfield. That's really the only answer. Pogba goes down, Felliani goes down, and now there is no one who can really retain possession in the attacking half of the field anymore. Herrera, Matic, and Carrick just aren't built for that.
All there is to it, really.
Manchester United fist few game of the season were a wonder to watch, at last, it seem the team had returned to a more attacking style of play, then suddenly, recently, they have gone back to a more defending style which is pretty sad to me. I know they have been a lot of problem with injury but for me, its still make no sense, they still should have enough quality to score a few goal a game, so why don't they try to actually go out there and attack. Its just doesn't make any sense to me. Can anybody help me understand what happened to them?