Ferguson's case for the defense

Sir Alex Ferguson is convinced a strong backbone will be the key to Manchester United enjoying another memorable Champions League away-day on Tuesday night.

Victory for the Red Devils against Bayern Munich in the Allianz Arena will be a tournament record seventh successive victory on their travels that dates back exactly 12 months.

The return of Wayne Rooney from a bruised foot has already been hailed as potentially pivotal, and Ferguson is not about to demean the contribution of his 33-goal front-man.

But, for the United boss, having Rio Ferdinand fit after a groin injury is equally important, as his central defensive partnership with Nemanja Vidic is the rock upon which his team's hopes are being built.

"The return of the Vidic and Ferdinand to keep our back four solid is significant," said Ferguson.

"Along with Edwin van der Sar there was a time when all those players were injured. It wasn't easy and we were very fragile.

"But you can see the solidity now. You can see the experience of these players and it is making a massive difference to the performances of the team.

"It is a true saying strong at the back, strong as a team. We are looking very strong now."

Ferguson is also now aware that Vidic will escape any FA action for his challenge on Johan Elmander at Bolton on Saturday that drew such a stinging rebuke from Trotters chief Owen Coyle, who labelled it a "terrible tackle".

The United camp did not see the incident in the same way, and neither did referee Martin Atkinson, who confirmed he had a clear view.

"What is the old saying about people in glass houses?" countered Ferguson. "When Nemanja Vidic came off at half-time he had a lump on his head the size of an egg, his jaw was swollen and he had a black eye.

"I didn't see them all but I know it was the best central defensive performance in the world this weekend.

"It was the best central defensive performance I have seen for years."

As United have not failed to reach the last four since Vidic arrived from Spartak Moscow four seasons ago, the Serbian is clearly a major factor in their new-found stability.

Ferguson senses a general improvement, which gets United to the level he has been trying to attain for so many years.

"We have matured as a team in Europe," he said.

"Our away record over the last two or three years has been fantastic.

"It is 17 games undefeated away from home now. That is an indication of the team's maturity and understanding of how to play in Europe.

"There have been some fantastic challenges in those 17 games.

"But we accepted the challenge of the weaknesses away from home in our game some years back.

"We have addressed them properly now."