The 29-year-old world player of the year, who moved to the Bernabeu in the summer of 2009 from Manchester United for a then world record £80million, would love to return to Old Trafford – but a move to rivals Manchester City could also be an option.

It’s something United insiders have been made aware of but whereas the commercial arm of the club would welcome him back with open arms the final decision would come down to manager Louis van Gaal.

Although the Portuguese star would be 30 next summer Real Madrid would still expect a fee in the region of £60 million with little long term sell on value.

And with United committed to a £54 million permanent deal for the on loan Radamel Falcao, Van Gaal might believe the money would be better spent elsewhere.

There could be more likelihood that Ronaldo would end up at neighbours Manchester City who have tried to tempt him back to the Premier League in the past.

Paris Saint Germain have been courting Ronaldo for the past 12 months and would strengthen their resolve given any encouragement.

But what is certain is that time is running out for Ronaldo at the club he once dreamed of joining leaving many of Europe’s top sides on red alert.

Meanwhile Van Gaal will concentrate his transfer ambitions on two long standing targets, Roma’s Dutch international Kevin Strootman and Borussia Dortmund’s German World Cup winner Mats Hummels.

Once midfielder Strootman proves his fitness after a cruciate knee injury Van Gaal will make his move while he has told United’s money men to make Dortmund an offer they can’t refuse for central defender Hummels.