Ruud van Nistelrooy told Cristiano Ronaldo he ‘belongs in a circus’ in Manchester United training ground bust-up which inspired Portugal star to be the best

Rio Ferdinand has lifted the lid on a training ground bust-up between Ruud van Nistelrooy and Cristiano Ronaldo which inspired the Portugal international to become the best in the world.

Ronaldo moved to Old Trafford in the summer of 2003 from Sporting Lisbon in the immediate aftermath of David Beckham’s departure to Real Madrid.

The floppy-haired teenager literally transformed himself from a scrawny winger to one of the best goalscorers in the world, culminating in a move to the Bernabeu himself for a world record £80million.

Ferdinand, who played alongside Ronaldo for those five years, believes it was his dedication and mental resilience which helped turn the now Juventus star from ‘a boy to a man’.

However, there were moments along the way which must have made even the resolute Ronaldo question if he belonged at Old Trafford or could even fill Beckham’s iconic No.7 shirt.

Ferdinand claimed an altercation with Van Nistelrooy in training after failing to provide a simple pass for the Netherlands striker prompted an outburst which would eventually inspire Ronaldo to ditch the tricks and focus solely on becoming the best.

“It didn’t happen instantly but he was unbelievably skilful and he was there to entertain the crowd,” Ferdinand said on BT Sport on Thursday. “He loved doing skills.

“He used to get snapped in training but I remember one time, I think it was a good moment for him but he didn’t take it too well. Ruud [Van Nistelrooy] was the man at United at the time. He was the man who scored all the goals.

“Ronaldo had the ball wide and was doing tricks and Ruud was making the run in the box, Ronaldo didn’t pass and Ruud went crazy, screaming. ‘He should be in the circus, he shouldn’t be on the pitch,’ Ruud said, and walked in, off the training pitch, and Ronaldo got upset and angry – ‘Why is he talking to me like that?’

“He was 18 or 19 at the time. Some kids would’ve gone under and lost confidence. Some would’ve kept doing the same but Ronaldo knew that Ruud might be right and then it became all about numbers, about statistics, goals. What is going to make him the best player in the world?

“We used to say to him, take the mick out of him and say, ‘You are not the real No. 7 at the club, you’ve got George Best and Beckham’ and you could see him thinking, ‘How can I derail them?’”

When Van Nistelrooy left United in 2006 to join Real Madrid, Ronaldo assumed the mantle of the main man at Old Trafford and formed a lethal partnership with Wayne Rooney and Carlos Tevez.

He would score 118 goals in 292 games under Sir Alex Ferguson and the 35-year-old is under no illusions he is the best player in the world, something Ferdinand attributes to his obsessive mind-set.

The former England captain added: “When we were going to a premiere, he was asked, ‘Who’s the best player ever?’ and Ronaldo said, ‘Me’.

“He’s got an ego but he’s got pride and an obsessive nature and came as a kid and left as the best player in the world.”