Manchester United's 'cartoon' defending a worry ahead of derby against Manchester City admits Alex Ferguson

United conceded three goals against Reading at the weekend

Sir Alex Ferguson is scared Manchester United's cartoon defending is going to prove very costly in Sunday's Manchester derby.

Ferguson appeared to dash hopes of Nemanja Vidic returning to lend a hand when he ruled the Serbian out of tomorrow's Champions League encounter with CFR Cluj at Old Trafford.

United need some sort of assistance, though. In conceding 32 goals so far this season, including three in quite awful fashion at Reading on Saturday, Ferguson said he could not remember a time when his side's defence had been so leaky this side of Christmas.

It was actually 2001-02, when United conceded 39 goals in their first 23 games, and 41 before Santa made his way down the chimney.

Clearly, though, it is no laughing matter for Ferguson, especially when he considers what is lying in wait on the other side of town this weekend.

"It is a worry," said Ferguson.

"If we perform like that on Sunday then God knows what's going to happen to us.

"We've lost 32 goals already - I can't remember us losing so many goals before Christmas.

"Saturday was like Cartoon Cavalcade and when you see City have Balotelli, Dzeko - really tall players - it's going to be a big challenge.

"It's a concern. But that's on Sunday. It's five days away but at this moment in time it feels like five months."

Ferguson's reasoning is that there are so many issues to resolve by then, focusing on a game which is not right in front of him is pointless.

Yet, history suggests the United boss is not beyond clouding the issue himself in order to suit his own ends.

So, whilst Ferguson's words on Vidic's readiness to play after September knee surgery were clear enough, until the Serbian actually fails to make the United squad, either tomorrow or at the weekend, they will be greeted with some degree of scepticism.

"I don't think Nemanja will play (tomorrow)," said Ferguson.

"He feels he needs another few days' training so he won't be available.

"He's not far away. He's training well now but I think another few days will bring him on better.

"But if he doesn't play tomorrow there's no chance he'll play in the derby game, although I wasn't considering Nemanja for Sunday anyway."

There is something contradictory about the last statement, especially as the United boss also raised the potential for Shinji Kagawa returning after two months out this weekend, even though Vidic trained with the main group at Carrington this morning and the Japan international did not.

"Kagawa started running today and may make the bench [against City]," said Ferguson.

"The injury has taken longer than we thought but he's much better now."

The Red Devils are resigned to wide men Nani and Antonio Valencia missing out, though, which is why Ferguson is likely to use three strikers tomorrow, including Wayne Rooney.

More than once this season, Ferguson has raised the issue of Rooney's fitness after injury lay-offs.

And even though the England man's most recent absence with tonsillitis only amounted to two games in the middle of last month, Ferguson is not intending the 27-year-old to be one of the star men who gets a rest tomorrow.

"Wayne needs to play a lot of games to get his match-fitness up," he said.

"He's a strongly built lad and when he misses two games it takes him three games to come back.

"It's the way he's always been.

"He'll play tomorrow night and hopefully that brings him on further because Saturday was his best performance of the season so far."

PA