Wayne Rooney has admitted Manchester United's performance in Sunday's derby-day hammering by Manchester City was "simply not good enough".

United were beaten 4-1 by Manuel Pellegrini's men, their worst away loss in the fixture since 2004.

Out-maneouvred in midfield, where £27.5million new-boy Marouane Fellaini was a particular disappointment, the Red Devils conceded three goals in a six-minute spell either side of half-time that left them staring down the barrel of total humiliation.

As it turned out, a combination of City easing off and Rooney grabbing a late consolation meant the damage was not as extensive as had appeared likely.

Still, for a team used to setting such high standards, Rooney knows the performance was not acceptable.

"It is not good enough," the 27-year-old told MUTV. "We know we have to improve and stop giving these sloppy goals away. It is not nice to lose to City. It was a bad result and we are all extremely disappointed."

Manager David Moyes excused Rooney from blame, claiming the England man did not deserve to be on the losing side.

His goal - a fourth in three games - means he has now become the highest scorer in derby matches with 11.

It is not an accolade he is taking much pleasure from.

"It is nice to score but it means nothing," he said. "The most important thing was the points and we have come away with none."

Given the tough baptism he has endured as United boss, it was perhaps no surprise Moyes should find himself paired together with Liverpool in the Capital One Cup as well.

The Reds will be bolstered by the return of Luis Suarez, giving an additional twist to an already high-octane occasion.

But Rooney recognises it provides the perfect opportunity for United to bounce back.

"We have all grown up, whether it is Manchester, Liverpool or somewhere else having local derbies," said Rooney. "It is not nice when you lose one. I have been there as a fan and now as a player. Thankfully we have another massive game against Liverpool.

"It is the ideal game for us. Any game against Liverpool, whether it is a friendly, Capital One Cup or Premier League, is massive. We have to try and get the victory so we can put this defeat to the back of our minds."