Sir Alex Ferguson has urged his players not to get carried away by Wednesday's staggering victory over AC Milan. The four-goal triumph over the seven-times European Cup winners will go down as one of Manchester United's finest European achievements. Once the fuss over David Beckham's green and gold exit and another two goals for Wayne Rooney has died down, the record books will show a superb aggregate win over a fellow heavyweight that in the short-term has dispelled any remaining concerns about United's ability to challenge for major honours this season. Ferguson recognises the enormity of the result. But, ahead of Sunday's encounter with Fulham, the Scot is also eager to introduce a note of caution. "We have to calm ourselves down a little bit," he said. "It was an emphatic result on Wednesday but they lost Alessandro Nesta on the morning of the game and then lost their centre-back at half-time. That made it difficult for them. "It is the same as when we played Fulham a couple of months back. We had no centre-backs, so what do you expect?" What the week's results did do was place a sense of perspective over Ferguson's refusal to spend the vast majority of that world record £80million received from Real Madrid for Cristiano Ronaldo. Ronaldo form One of the arguments put forward by the Manchester United Supporters Trust for their opposition to the Glazer family's ownership of the club is that their massive debt prevented Ferguson plunging into the transfer market. It is a claim which has been denied by senior figures within Old Trafford, including Ferguson himself, who stressed he has been put off by the vast prices being quoted for players little better than the ones he already has. That inflation was fuelled by Real and Manchester City. City have known since last month there would be no end to their 34-year wait for a trophy - the Carling Cup semi-final defeat to United being part of the wreckage - whilst the sight of Ronaldo shaking his head as he made his way off at the Bernabeu in midweek after Champions League elimination to Lyon was further proof money does not automatically buy success. "Spending money never has guaranteed you anything," said Ferguson. "It is not always the case it doesn't. But it is never a certainty. "I am just glad that we are into the next stage. That is all we need to concern ourselves with. "But I am disappointed for Ronaldo not having qualified. We had someone at the game and the report was he was absolutely fantastic. "In my mind I had a thought that somewhere along the line we were going to meet them and Ronaldo would be up against us. We would have needed a machine gun to stop him. "But it just shows you what European football is like. You get tricky games. "Bayern Munich, Lyon and Arsenal are already through, plus either Chelsea or Inter and probably Barcelona, so there is not going to be an easy game now." What do you think? Have your say.