By Manchester correspondent Alex Stevens

Manchester United’s players used to wind up Cristiano Ronaldo by telling him that David Beckham was the “real number seven”.

Ronaldo inherited the symbolic United number worn by Beckham, Eric Cantona, Bryan Robson and George Best when he moved to Old Trafford in 2003.

Rio Ferdinand recalls how a group of first-teamers, including himself, Wayne Rooney, Darren Fletcher and Quinton Fortune, used the shirt to inspire the Portugese winger when he was making his name at Old Trafford.

“We’d be in the changing room and a few of us – me, Quinton Fortune, Fletch and Wazza etc – used to say to him, ‘Ah, Becks is the real number seven, he’s the Daddy, he’s up there and Ronaldo’s down there’,” explained Ferdinand.

“He used to go mad in training. You could see it boiling up inside him, because he’d be that desperate to be a superstar and be the best.”

Ferdinand says Ronaldo has used his rivalry with Lionel Messi to take his career to greater heights, and other players should follow suit.

“Having Messi there, he needs that stimulant, he thrives off it,” said the former England international. “They’re head and shoulders above the rest but they’re going at each other all the time.

“The best players accept a challenge. Speaking to agents, the stuff they have to deal with in terms of the fragility of players…’ah, there’s other players in my position in the club, what am I going to do?’ They’re so fragile it’s unbelievable.

“The ones who get to the top and stay there are the ones who see that challenge and say, ‘yes, I’ll have it with him’.”