It's Wayne's world -- but where?

The availability on the open market of a player of Rooney's calibre could normally be expected to trigger a frenzied bidding war. Yet the astronomical salary demands Rooney is likely to seek from anyone wishing to sign him mean that only a handful of super-rich clubs are likely to possess the financial muscle to secure his services.

If cold, hard cash ends up being the defining criteria of Rooney's transfer, the 24-year-old could well end up at United's cross-town rivals, Manchester City, who are bankrolled by the billionaire Sheikh Mansour.

City already pay midfielder Yaya Toure an estimated 220,000 pounds a week, and would have little difficulty in meeting Rooney's salary demands, or the 50-million-pound price tag likely to be demanded by United.

A move to City may also appeal to Rooney and his family on geographical grounds. His wife Coleen is believed to be reluctant to move abroad because her 12-year-old sister suffers from the rare genetic disorder Rett syndrome.

But whether United would be able to stomach the sight of Rooney plying his trade at Eastlands, barely one year after seeing Carlos Tevez jump ship in an acrimonious move, remains another matter. The Guardian newspaper commented that any move by Rooney to City would represent the "most rancorous and staggering transfer of modern times."

Yet the alternative for United -- seeing Rooney leave for a dramatically reduced fee as his contract winds down -- is equally unpalatable. If, somehow, City are ruled out of the running, the only realistic option for Rooney in England are reigning champions Chelsea.

While the club has reined in spending in recent seasons, taking a more selective approach in the transfer market and keeping a firm grip on salaries, billionaire owner Roman Abramovich does have the cash to make a deal happen.

Manager Carlo Ancelotti indicated earlier this week that Chelsea would be interested in Rooney if he became available but later backtracked. "I don't like it when some coaches speak about my players and I don't want to do the same for players of other teams," Ancelotti said. "I have respect for United and I have respect for Sir Alex Ferguson. It's their problem."

Daily Mail sports writer Martin Samuel argued that Chelsea would be the most "sensible" option if Rooney wished to stay in England. "They pay big money, they win titles, they would suit his style and in London he may find the anonymity he must crave after a traumatic year in the spotlight," Samuel wrote.

If Chelsea and Manchester City represent the only realistic English suitors for Rooney, the pool of possible overseas clubs is just as shallow, with only Real Madrid and, less likely, Barcelona in the frame. Of the two Spanish clubs, Real look the more logical fit, having the edge over Barcelona who have recently announced steep losses.

Jose Mourinho is a long-time admirer while a move to the Bernabeu would also see Rooney reunited with former Manchester United team-mate Cristiano Ronaldo, with whom he formed a lethal attacking partnership.

The problem is that Real Madrid already have an embarrassment of attacking riches, with the likes of Ronaldo, Gonzalo Higuain, Angel Di Maria and Mesut Ozil all in the team. "Who do we take out if Rooney comes?" Real's technical director Jorge Valdano said on Monday.

Before news of Rooney's disenchantment at United broke however, Mourinho had said Rooney was the player he would most like to coach. "It's an impossible dream -- Wayne Rooney. As much for his brilliant mentality as for his football talent."