David Beckham has urged Real Madrid ace Cristiano Ronaldo to rejoin Manchester United if the opportunity presents itself.

Speculation has mounted that the 30-year-old will consider his Madrid future at the end of the season, having joined the Blancos for a then-world record £80m from United in 2009.

Red Devils legend Beckham made the same switch as his Portuguese counterpart in 2003, admitting that it was a "dream" to join the Spanish giants, but concedes that he would have "crawled back" to Old Trafford afterwards.

"I'd never advise anyone not to come back to United," Beckham is quoted as saying by ESPN. "I'd have crawled back if I could. But then obviously given the chance once I'd left United, to have played for one of the biggest clubs in the world - with Real Madrid, again it was a dream. But I'd never advise any player to not return to Manchester United.

"Cristiano is such a fans' favourite at United, he was so successful, such a hard worker. Everyone you talk to, that has played with him, been around his world - he's not just one of the most talented players in the game, he's a hard worker as well.

"If he decides to leave Real Madrid then for me personally it's back to United. I never had the opportunity to do so - but I'm proud of the teams I played for after United."

Ronaldo usurped Raul as Real's record goalscorer of all time in September.