United are expected to be at the front of the queue for Ronaldo, who they originally signed from Sporting Lisbon in 2003.
Ronaldo, 32, is said to be miffed over claims by authorities that he defrauded the Spanish taxman of €14.7million during his time at the capital, an allegation he has refuted.
Manchester United are plotting an incredible offer to bring Cristiano Ronaldo back to Old Trafford. But, if he's made his mind up, I don't think it's going to be easy to change.
"He says I want to leave and that's it, as a president you can't do anything other than let him go and get the best possible deal".
Together with Barcelona's Lionel Messi, the presence of Ronaldo at Madrid has helped LaLiga cement its status as one of the most attractive competitions in world football, leaving Tebas concerned at the prospect of the Portugal worldwide quitting Zinedine Zidane's side.More news: House GOP Whip Scalise remains in critical condition, hospital says
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Paris-Saint Germain, AC Milan under new ownership and China appear to be the only financially realistic destinations for the Portugal worldwide but a return to England representing the Red Devils is apparently the priority, so we'll just have to wait and see how this one pans out over the course of the transfer window.
"Sir Alex Ferguson was like a father and he loved the fans".
The problem for Ronaldo is that very few clubs could afford his wages on top of what would be a massive transfer fee.
The Daily Mail claim that Ronaldo and his agent Jorge Mendes have already held secret talks with Paris Saint-Germain just hours before the Champions League final, a fact that makes them the favourites in their eyes.
The pair were also caught deep in discussion during Portugal's 2-2 draw with Mexico, with Ronaldo saying "they are very bad" to Pepe as they returned from the half-time break.