Sir Alex Ferguson has conceded that his Manchester United side's defensive performances so far this season have given him cause for "concern" ahead of this Sunday's Manchester derby.
The Red Devils have already shipped 32 goals in all competitions prior to tomorrow's Champions League encounter with CFR Cluj and the meeting with Manchester City at the weekend.
Looking ahead to the derby, Ferguson has admitted that his side will have to improve dramatically from the defensive showing that they produced against Reading on Saturday evening.
"I think we're getting punished when the ball's going into our box at the moment," he told reporters. "But we should be defending far better. Albeit, Reading produced some fantastic balls into the box. We should be expecting better. It's a worry. If we perform like that on Sunday, then God knows what's going to happen to us.
"When you see the goals against - we've lost 32 already - I can't remember us losing so many goals before Christmas. It's a concern, there's no question about that.
"When you see City have Mario Balotelli and Edin Dzeko - all really tall players - it's going to be a big challenge."
United head into the derby three points clear of rivals City at the top of the Premier League table.
