Real Madrid's Cristiano Ronaldo celebrates his goal against Osasuna during their Spanish First Division soccer match at Santiago Bernabeu stadium in Madrid April 26, 2014.
Cristiano Ronaldo Reuters

Manchester United legend Sir Bobby Charlton has revealed that he remains hopeful that Real Madrid star Cristiano Ronaldo will return to Old Trafford.

The Portuguese international left the Red Devils and joined the Spanish capital club in 2009, after spending glorious years with United. He won the Champions League with Real this May and the 2013 FIFA Ballon d'Or in January.

The 29-year-old signed a long-term contract with Real in September and it will keep him at the club till 2017.

Charlton, who is also a director at Old Trafford, admitted that it is a treat to watch Ronaldo in action and believes the former United star may not re-join the Red Devils in the future.

"I wonder if ever the day would come when maybe he would come and play for us [Manchester United] again," Charlton told Laureus.

"I don't think it will happen, but you never know. He is the most enjoyable player to watch that I've ever seen. He is so fast, so inventive, just magic."

United endured a poor run last season and finished seventh in the league table under the guidance of David Moyes. The club will not feauture in next season's Champions League.

The Red Devils sacked the former Everton boss just 10 months into his six-year contract and appointed Louis van Gaal as his successor.

The former Barcelona and Bayern Munich boss will take charge once he steps down from the Holland post after the World Cup campaign.

Charlton believes United will make it to the top once again and has backed Van Gaal to be a success at Old Trafford.

"We've had a really, really tricky year and I'm quite hopeful that it won't be long in the future before we actually line up to perform against the best. We've got a new manager, new outlook, a new style," the United legend said.

"It'll be very interesting to see how he comes along and how he works. He's obviously a, very important person with regard to the Dutch. I think that he will certainly be a very, very good performer for us," Robson concluded.