Manchester United have been linked with an audacious move to bring Real Madrid forward Cristiano Ronaldo back to Old Trafford. The Daily Star claims that United could land the Portugal international for £55 million and are devising an inventive way to fund his £220,000-a-week wages.

There has been speculation over Ronaldo’s future for much of the season, with reports that he does not feel sufficiently valued at the Spanish champions. The 28-year-old has so far refused to commit himself to the club beyond the end of his current deal in 2015, although he has said that he will remain with Madrid at least until that point.

Yet, the Star’s story states that Ronaldo’s representatives are already investigating commercial opportunities to link in with a potential return to the Premier League. It is said that a deflation in transfer fees would lead to Madrid requiring a full £25 million less than they paid United for Ronaldo in 2009.

Such a claim appears doubtful. Nouveau-riche clubs like Manchester City, Paris Saint-Germain and Anzhi Makhachkala are prepared to operate almost as if money were no object when the world’s top players become available. It is hard to imagine Madrid not being able to attract an offer of at least equal to what they paid for Ronaldo, unless the player were to run his contract down.

The story also asserts that United would part-fund Ronaldo’s wages by the player signing separate endorsement deals with the club’s sponsors.  It is a method that is widely used in Brazil and has allowed clubs to both keep young players, like Neymar for longer, and also bring back established stars earlier in their careers.

Despite the mutual affection between the player and the club, a return to Old Trafford for Ronaldo still appears highly improbable at this stage.

Ronaldo’s Portugal teammate Nani may soon be heading through the exit door at United, however. The Independent has reported that the winger is resigned to leaving the club this summer due to a lack of first-team opportunities. The latest blow to Nani came when he was left out of the squad that took on Real Madrid in the first leg of the Champions League last-16 tie last week.

Despite Nani’s match-winning performance against Reading on Monday, United manager Sir Alex Ferguson has now revealed that the club has so far been unable to persuade the 26-year-old  to extend his current contract, which expires in the summer of 2014.

"[Chief executive] David [Gill] has been speaking to [Nani's] agent for quite a few weeks now," Ferguson said, according to the Independent. "It's up to the boy himself. He's got a year and a half left, I would prefer to keep him to the end of his contract.

“But I think he wants guaranteed first-team football. But he can guarantee that. His performance the other night can guarantee that. We're trying our best because he's such a match-winning player."

Meanwhile, the Daily Mirror has become the latest outlet to claim that Real Madrid are lining up United goalkeeper David de Gea as the long-term successor to Iker Casillas as the Bernabeu.

There have also been strong suggestions that United are set to swoop for Stoke City keeper Asmir Begovic this summer. De Gea, 22, has been the subject of much media criticism for his inability to deal with the physicality of the English game. Ferguson, though, recently vehemently defended the £18 million signing from Atletico Madrid and De Gea has since put in a superb performance against Real Madrid last week.

Casillas’ relationship reportedly broke down with manager Jose Mourinho this season, leading to him being dropped for several games before he suffered a broken hand. Yet, with Mourinho looking highly likely to leave Madrid this summer, Casillas’ future would not appear to be in doubt.

At 31, Casillas is still in the prime years for a goalkeeper and it is hard to imagine De Gea moving somewhere to be a back-up, potentially for several seasons.

In terms of potential signings this summer, the agent of Hamburg striker Heung-min Son has claimed that Manchester United have made an offer for his client.

The 20-year-old South Korea international has scored nine goals in 21 Bundesliga appearances this season. Son only recently signed a contract extension, but it only ties him to Hamburg until 2014. And agent Thies Bliemeister has said there is interest in the player from some top clubs.

“Inter Milan's emissaries saw a couple of his matches, but so far I have not had any contact with the Italian club's officials," he said, according to Sky Sports.

"A transfer in the next summer? He has signed a new contract with Hamburg SV extending it for one year, but there have been many offers for him as from Manchester United and Chelsea.”