United wait for news on Scholes scan

With Owen Hargreaves and Michael Carrick already sidelined, Ferguson can ill afford to lose Scholes for an extended period too, especially with a key Premier League confrontation with table-toppers Arsenal looming on November 3, so he will desperately hope rumours of an operation being required proved unfounded.

"We do have strength in depth but the most important thing just now is that the changes we are making are not affecting our performance," said Ferguson. "Paul got an injury in training, which will require a scan."

Scholes' presence is still key to United's chances of success this term, although no-one would have guessed it as John O'Shea and Darren Fletcher stepped into the breach at the Olympic Stadium as United romped to their biggest away-day success in Europe for nine years.

Ferguson added: "We also lost Patrice Evra with a calf strain in the warm-up but John and Darren came in and were excellent.

"Those two have been with us for a long time and understand what playing for this club is all about. But Carlos Tevez, Nani and Anderson joined us in the summer and have adapted really well to English football."

Victory in the rematch at Old Trafford in a fortnight will ease Ferguson's side into the last 16 with two matches to spare.

"We have nine points now, which puts us in a great position," said Ferguson. "To score four goals away from home in a European game is an excellent performance at any time and we could have scored more.

"Our forward play at the moment is excellent and although the goals looked easy, you have to be there to take them."