Manchester United believe an Old Trafford return for Cristiano Ronaldo next summer will prove almost impossible, it emerged on Friday.

United supporters are praying their former hero comes back from Real Madrid to end his career with them next summer.

However senior Old Trafford sources told Sportsmail that they believe the cost of bringing the World Player of the Year back to the club will in all likelihood prove prohibitive for a player who will be halfway towards his 31st birthday by the start of next season.

VIDEO Scroll down to watch Ronaldo return to United could cost £60m

Real Madrid superstar Cristiano Ronaldo has been linked with a move back to Manchester United

A United fan group flew this 'Come Home Ronaldo' banner over Real's win over Villarreal last weekend

It emerged last week that Ronaldo’s representatives were asking for £20million a year in wages when the Portuguese star was touted around in the summer of 2013. Add a transfer fee of about £60m to that and the cost of the deal becomes clear.

A United source said today: 'Ronaldo will always be loved here.

'But if you look at the numbers and his age than you have to ask if it really could be made to work.

'We are not at all sure it can.'

Ronaldo made his name at Manchester United, signing in 2003 before moving to Real six years later

Ronaldo celebrates winning the 2008 Champions League in Moscow with Sir Alex Ferguson

VIDEO Ronaldo return to United could cost £60m

RONALDO AT UNITED Matches: 290 (2003-09) Goals: 117 Honours: 3 x Premier League 1 x FA Cup, 2 x League Cup 1 x Champions League 1 x FIFA Club World Cup Advertisement

United believe that their best chance of buying Ronaldo back was actually last summer when he made it clear to them that he was unhappy with life at Real.

Club insiders believe that had former manager Sir Alex Ferguson been in charge then the deal may well have happened. A new United team would then have been built around him.

As it was, David Moyes was in the first stages of his own short reign at that point and ultimately United believe they were led on by the Ronaldo camp as he tried to engineer a new contract at the Bernabeu.

The Portuguese forward celebrates scoring for Real in the Champions League this week

Ironically, it is that deal – eventually signed last September – that now makes it so difficult to bring Ronaldo back to the club where he first came to the world’s attention.

With Ronaldo contracted now until 2018, Real president Florentino Perez holds all the cards in terms of dictating a fee for the club’s prize asset.