Real Madrid star Cristiano Ronaldo has spoken of former Manchester United manager Sir Alex Ferguson's fiery temper.

Speaking ahead of the BBC's upcoming documentary, 'Sir Alex Ferguson: Secrets of Success,' which will be aired at 10.30pm on October 11, Ronaldo revealed the full extent of the Scot's wrath.

"I remember sometimes when we do something bad or we lost some games he kick the chairs and he kick the boots, he kick everything, the waters, the drinks, and he's so red and 'f**k you, you should pass the ball you," said the Real Madrid forward.

"It was unbelievable but it was good - because we learn."