Rio Ferdinand details what really makes a footballer ‘world class’

Rio Ferdinand has responded to Sir Alex Ferguson's claim that he only considers four of his former Man United players to be 'world-class'.

Cristiano Ronaldo, Paul Scholes, Ryan Giggs and Eric Cantona were the chosen quartet, but the omissions of players such as Roy Keane, Ruud van Nistelrooy and Peter Schmeichel haven't gone down well with some fans. In a message on his Facebook page, Ferdinand lists "performing in the big games, consistency" and "a high level of ability in all areas of the game" among the qualities required. "That list could go on and on with many different areas to judge upon!" he said. "There is no common rule that serves up the criteria. It's a great debate to have amongst friends - we've all done it!"