Manchester United v Manchester City: Wayne Rooney warns 'everything could fall' with defeat at Old Trafford

United hold a 15 point advantage over their City rivals

Wayne Rooney: Showed glimpses of what United were missing against Real Madrid, but ultimately lost his grip on the game. 6 (Getty Images)

Wayne Rooney is acutely aware Manchester United can afford to take nothing for granted ahead of tonight's derby clash with City at Old Trafford.

With a 15-point advantage and only seven games of the Premier League campaign remaining, it seems certain the title is destined for United, even if City were to prove the victors this evening.

Rooney is following manager Sir Alex Ferguson's lead in having none of it, knowing one defeat can soon spiral into a downturn of more significant proportions.

"One bad game and everything could fall and so we go out and play each game with a positive attitude," Rooney told the Daily Mail.

"We have to stay focused. We have to make sure we keep doing our job and keep our concentration."

In the aftermath of last season's final game, when United were technically champions when the whistle blew at Sunderland, only for Sergio Aguero's injury-time effort for Manchester City against QPR to break their hearts, it was claimed Ferguson strode down the team bus on the journey home to implore his younger players never to forget the experience.

Ferguson has denied saying it.

But it is clear those memories run deep.

"To lose the league in the last second (last season) was a bad feeling," said Rooney, who is hoping to feature after recovering from the groin injury he suffered on England duty in Montenegro.

"But when you are at a club like United, you have to be full of motivation and desire to win every year.

"That comes from the manager and all the players are aware of it.

"The club and the players have to be full of that desire. That's why the club has been so successful."

PA