By FOX Sports Staff
Real's last visit to Old Trafford was an amazing occasion that finished 4-3 to United thanks to two goals from David Beckham and a comeback that followed a hat-trick from Brazilian forward Ronaldo which earned him a standing ovation from the Stretford End.
The spectre of Ronaldo remains when Real make their return on Tuesday. Only this time it is the man who once delighted the Old Trafford faithful rather than the one who remains the highest goalscorer in World Cup history.
Ferguson is wary of the threat that their former star pose, but vows to not let it overwhelm his players.
"The older one, the fatter one, peaked as a centre forward at that time," said Ferguson.
"(Cristiano) Ronaldo is a supreme athlete. He never misses a game, has fantastic physique, two great feet, pace, he is good in the air.
"My biggest concern is if he turns up because you expect problems.
"We have to try and curtail that as best as we can. It won't be easy because he does it every week.
"But it isn't something we should fear. If we go in worried about the damage Cristiano can do we forget what we can do ourselves."
Ferguson is anticipating a mouth-watering encounter at Old Trafford with both teams coming into the match in fine form.
Real Madrid are on the back of two Clasico wins over arch-rivals Barcelona, the first of which saw them destroy the Catalans 3-1 at the Nou Camp while the Red Devils are are currently 15 points clear at the top of the Barclays Premier League following Saturday's 4-0 victory over Norwich.
He said: "I think that both teams are in form.
"(They have given) two fantastic performances against Barca.
"I saw the first one and (they were) absolutely superb. They have found form at the right time for a game of this nature.
"Our form has been consistent for quite a while and we will need that form tomorrow [Tuesday] night.
"They are two great clubs with great histories and it's set up to be a potentially marvellous game. I don't think it will be a disappointment."
The manager has also confirmed Phil Jones has lost his battle to be fit for Tuesday night's Champions League clash with Real Madrid.
Jones injured his ankle in the FA Cup win over Reading a fortnight ago and has not recovered sufficiently to face Madrid in the last 16 second-leg clash at Old Trafford.
Ferguson admitted the loss of Jones was a blow, given the England man's performance in the first leg, but was confident it was one his side could overcome.
He said: "He's not fit. He won't be fit for tomorrow [Tuesday]."
"His performance over there was excellent but we do have options and hopefully it is something we get right," he said.
Veteran midfielder Ryan Giggs will be involved, however, on what will be his 1,000th senior competitive appearance for club and country.
Ferguson added: "He played against QPR and I always think with Ryan that you like to keep him fresh.
"Tomorrow [Tuesday] he will be involved at some point, whether starting or on the bench - I have not made my mind up but he will be involved. Of course his experience of big occasions will be vital to us."
Giggs himself is also eagerly awaiting the game, which he foresees will be filled with goals.
"It was two great sides and there were so many goals. It could be similar tomorrow [Tuesday]," said Giggs.
"When you have that much firepower on the pitch, undoubtedly there are going to be chances and goals."