The problem they have is that because Ronaldo is such a one-off, they will effectively have to replace two players. They probably needed a new winger anyway, but boy do they need one now. Add to that the need to replace their top scorer of the past three seasons, so they will most likely have to buy a winger and a striker. Here are a few possibles for that money...
Sergio Kun Aguero - Atletico Madrid
He makes our man in Spain go weak at the knees, is unreasonably skilful and has a child with genius in his blood. As you probably know, the Argentine is Diego Maradona's son-in-law, but more importantly banged in 22 goals for Atletico Madrid last season. Would provide both goals and invention, although nothing close to the physical presence of Ronaldo. He has had problems playing with Carlos Tevez for the national side, so if he is retained then the chances of Aguero joining too would be slim.
Potential Value: £40million.
Karim Benzema - Lyon
Raw potential at the moment, but what potential. Benzema would bring the pace and power that Ronaldo had, and at the same time provide the attacking focal point that United have lacked of late, and were arguably able to get away without because of Ronaldo. Lyon president Jean-Michel Aulas knows how to drive a hard bargain, but even he would not be able to resist the sort of sums that United now have at their disposal.
Potential Value: £30million.
Samuel Eto'o - Barcelona
United need a proven goalscorer to step in for Ronaldo, and goalscorers don't come much more proven than Eto'o. Since joining Barcelona in 2004, Eto'o has thwacked in 130 goals in 200 games, a record that few can rival throughout the world. The big downside is his ego. There can be no other reason for Barca apparently being fairly willing to sell for a relatively cheap price than an attitude problem, so would Fergie want to replace one massive I Am with another?
Potential Value: £15-20million.
Alexandre Pato - AC Milan
Bit of a long shot this, given that Adriano Galliani said on Thursday he was not for sale. However, Milan said similar things about Kaka in the past, and look what happened there. Pato is one of the most promising prospects in world football, and is at an age when Ferguson can shape him into his own kind of player. The other snag is that he might not be willing to leave the comfort of Milan for anyone but mentor Carlo Ancelotti. Like we said, it's a long shot, but Pato is one of the few big names left that might be prised from their clubs this summer.
Potential Value: £35-45million.
Franck Ribery - Bayern Munich
The most obvious direct replacement for Ronaldo, Ribery is also likely to be the most expensive. Word in the papers on Thursday was that Chelsea had been quoted a whopping £65million for the Frenchman by Bayern Munich, and it's hardly surprising. The purchases of Kaka and Ronaldo have skewed the market to such an extent that anyone with a young talent like Ribery can now add a digit or two to their price. Able to play on both right and left, like Ronaldo, Ribery also scores plenty too, like Ronaldo.
Potential Value: Anything up to £65million.
Arjen Robben - Real Madrid
Injury-prone he may be, but Ferguson probably regards Robben as one of a number of players who escaped his clutches when he joined Chelsea in 2004. The bonus where Robben is concerned is that he'll be cheap, with prices as low as £7million being mentioned. If he can stay fit then he's still a massively destructive winger, and although that is a big if, to say that Robben is less than 1/10th of the player Ronaldo is would be ridiculous.
Potential Value: £7-10million.
David Silva - Valencia
Like Ribery, can play on either flank, provides plenty of skill and invention and is a natural left foot in the attacking third, something that United haven't had since Ryan Giggs became a midfielder. The problem is, not for the first time, Real Madrid, who are apparently on the verge of snapping him up from Valencia.
Potential Value: £20-25million.
Carlos Tevez - MSI
Would losing two fan favourites be too much for one summer? Ronaldo's departure could be the key factor in persuading David Gill to acquiesce to Kia Joorabchian's demands.
Potential Value: £25million.
Luis Antonio Valencia - Wigan
Strange one this. While a decent player, the prices being touted for Valencia seem rather high. He seems certain to leave Wigan, but one suspects he alone will be woefully inadequate as a replacement for Ronaldo. With another of the names on this list, he could perhaps develop into an excellent player, but we have our doubts.
Potential Value: £12-18million.
Ashley Young - Aston Villa
Ferguson has an obvious knack for bringing through young domestic talent, but very few have actually come from the famed academy of late. Ferguson has instead bought nearly finished youngsters and honed their skills, and although Young is not exactly new and unpolished, he might represent the sort of player who could thrive under Ferguson. Fast and tricky, he doesn't score an awful lot of goals, but then again neither did Ronaldo in his early days. Could prove pricey as Villa obviously do not need to sell.
Potential Value: £20-25million.
Nick Miller
