Before the international break, Arsenal thrashed United 3-0. And Van Gaal has revealed that it has been awful at the club.
United fell to defeat at the hands of Arsenal, with a Sanchez brace and an Ozil goal doing the damage.
Club manager, Louis Van Gaal says the atmosphere at the club has been awful, as he has failed to lift the mood of his players.
“When you have more than two weeks it is awful when you have such a result,” said the United manager.
“It has been an awful two weeks because before the last international break we lost against Swansea.
“It’s not only the players, it’s the staff, and my cook, Mike [Donnelly], because he has a big influence on the atmosphere in the canteen.
“So these are awful weeks, because you are constantly thinking about how it happened and you cannot manage it with your players, because that is what you have to do, but all the players were flying out.”
Van Gaal also insists that his side must not show a repeat performance when they face Everton at Goodison Park on Saturday.
“Arsenal had 96 per cent passing accuracy but we had 68 per cent, normally we have 85 per cent or something like that, so it is a big difference,” said the Dutchman.
“We have spoken about how that cannot happen again. We started so badly and Arsenal was so good. Maybe that was a coincidence but I don’t believe in that, I believe in preparation, focus and concentration.”