Cristiano Ronaldo
Cristiano Ronaldo's future remains the source of speculation. Reuters

Manchester United manager Sir Alex Ferguson wants to bring Cristiano Ronaldo back to Old Trafford this summer, according to the club’s former defender Gary Pallister.

With Ronaldo yet to agree to a new contract at Real Madrid, speculation has continued that he could be tempted to rejoin the club with which he became an idol to the fans between 2003 and 2009. The Portugal forward signed for Madrid in a record £80 million transfer and it appears unlikely that United would be able to afford both the enormous fee and wages to re-sign him.

However, reports have suggested that United were working on a proposal with sponsors to help fund a deal. Pallister, who played for the club between 1989 and 1998, believes that an incredible transfer may just be a possibility.

"I know for sure that Sir Alex would love to have Ronaldo back at Old Trafford,” he told Goal.com. “To be honest, I didn't think it would be likely, especially this summer, but I'm coming round to it now. A lot depends on whether Jose Mourinho stays at Real, but, if not, Ronaldo could be tempted into a return.

"Of course, if Ronaldo is available, United will have to break the bank to get him, but if it’s true that new club sponsors will be willing to underwrite the deal, then it might be an exciting summer ahead,” he added.

Ronaldo is not the only Madrid star being linked with United. The Daily Express, citing stories in Spain, is the latest publication to report on interest from Old Trafford in winger Angel di Maria.

It is claimed that his poor performances this season have frustrated both Madrid manager Jose Mourinho and president Florentino Perez to the point where he could be allowed to leave this summer.

However, while the 25-year-old’s displays were below par earlier in the campaign, he has been exceptional in the second half of the season and a key part of Madrid’s revival.

If United are to add another winger to their ranks this summer -- in addition to Wilfried Zaha -- then it appears likelier to be Porto’s James Rodriguez.

After yet another impressive season in Portugal, the Colombian continues to be linked with a move to Old Trafford. Porto are likely to demand a huge fee for the 21-year-old, however the Daily Mirror has suggested that United could offer a cash-plus-player deal involving Nani.

Antonio Valencia, Ashley Young and Nani have all disappointed on the flanks this season, yet it is the Portugal international who is most likely to be allowed to leave. Nani has just over a year remaining on his contract and has struggled to hold down a regular place throughout the campaign. The Mirror reports that his poor display in the FA Cup defeat to Chelsea last week has convinced Ferguson to dispense with the former Sporting Lisbon man.

There has also been further talk about reported Manchester United target Dede. The Brazilian central defender’s club Vasco da Gama recently conceded that they would have to sell the 24-year-old this summer.

Dede, however, has refused to be drawn on speculation linking him with United, Liverpool and Corinthians.

“I don't know anything. Corinthians are a great club and I won't say I wouldn't like to play there,” he said, according to Sky Sports.

"I'll arrive in Rio de Janeiro to know what's going on. But I'll keep focusing on my job."