Sir Alex Ferguson has admitted there was a sense of panic at Manchester United when Rio Ferdinand suffered his most recent back scare.

Ferdinand was forced to pull out of the Premier League win over West Ham last month after suffering a twinge in his back.

After spending three months on the sidelines with a similar problem that had plagued him for a year before that, it is little wonder Ferdinand was anxious.

He was immediately disregarded for the Carling Cup final, plus England's friendly against Egypt the following week, when he was supposed to be taking over from John Terry as captain.

Thankfully the problem proved to be short term and Ferdinand returned for last Saturday's victory at Wolves before producing a fine display alongside Nemanja Vidic in the midweek Champions League defeat of AC Milan.

"It was only a twinge, but Rio panicked a little bit, as we all did," Ferguson said.

"It felt like a case of "Here we go again," but he is fine and looking good.

"He is training well. He has never missed many training sessions since he came back. Hopefully it will continue like that."

Ferguson certainly feels at ease knowing Ferdinand and Vidic are back at the heart of his defence, given the Serbian was also sidelined for an extended period by a nerve complaint in his leg.

"When I see the two of them together there is a sense of security that we have been fighting all season for," Ferguson added.

"They have got the experience, authority and understanding with each other.

"Coupled with Edwin van der Sar coming back from a long-term injury, it makes an unbelievable difference.

"Any threat to us seemed to be stuffed out very early.

"That is an indication of the authority they bring to the team. I pray to the Lord they stay fit until the end of the season."