The European champions have reportedly used Gerard Pique to sound out his former team-mate about a switch to the Nou Camp.
Real Madrid would be delighted to team up Rooney with Cristiano Ronaldo, the Spanish giants' £80million summer signing from Old Trafford.
In the running: Barcelona hope to land Rooney (left) and will use Pique (below) to convince England's star striker his future lies at the Nou camp
United boss Sir Alex Ferguson is confident of holding on to the England striker and reports that the Premier League champions are struggling to meet his contract demands are thought to be wide of the mark.
However, revelations over the state of United's finances have put Spain's big two on alert.
Rooney's name was on a wish list drawn up by Madrid before Christmas, only for Bernabeu insiders to conclude it would be easier to go for either Atletico Madrid's Sergio Aguero or Valencia's David Villa.
However, the big spenders are now assessing whether United would be open to negotiation.
The England star would be an asset to any team in world football and is particularly admired for his ability to play anywhere in a front three.
With a presidential election due at the Nou Camp in April, May or June, Manchester United should be braced for prospective candidates pledging to sign their prized 24-year-old.
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