Steve Bruce has told his players they must get "back to basics" after their 5-0 horror show against Leicester City.
On a day in which the Magpies failed to conjure up a shot on target or a corner kick, Bruce admitted he felt let down by his team's performance.
He said afterwards: "We have worked on our defensive organisation and it has kept us in games but today we didn't have a left wing back and it made it difficult for us.
"It is a bad, bad performance.
"We have to go to work this week and put away the mistakes we have been making or it will be a long and difficult season.
"The second and third goal came so quickly and it became very difficult.
"It ended up as a horrible afternoon for everybody, I always knew it was going to be tough but now we have to show what we have got.
"We knew that we have a tough fixture list to start with but the Premier League demands you do the basics well, and if we don't against Man Utd, you will be in for a tough afternoon."
Bruce's own captain described the performance as "terrible", but the Toon boss said: "It was worse than that if I'm being honest, it was totally unacceptable.
"We have a following of supporters who have come here in their thousands.
"The way they supported us was typical of them but we have to give them more to shout about.
"The red card makes it difficult but you have to have more hunger.
"The deflection makes it a tough afternoon but certainly we didn't do enough, it was one of them horror shows."
Bruce was at a loss to explain some of the factors within the performance, he said: "It was not anywhere near good enough.
"We have made it difficult all afternoon and at 10 men you have to get 20, 30 minutes but we gave an awful goal away for the second and a deflection for the third. We have to show more than what we did and roll our sleeves up more in difficult circumstances.
"The mistakes, the way we went about he game, as soon as the third went in the heads went down.
"We did not do enough to stop the Leicester change.
"We need to do more.
"That is the difficult thing to take.
"We made mistakes and were badly punished."
