Rio Ferdinand claims Wayne Rooney was a player of greater talent than Cristiano Ronaldo when he arrived at Old Trafford a decade ago, but says it is through no lack of application that the new Manchester United captain has not reached the same heights his former colleague.
Rooney marked 10 years since his debut for Manchester United last weekend, and now stands among the club's greatest ever players. He was awarded the armband in the summer, while Sir Bobby Charlton's long-standing goals record is within reach.
But there are those who believe Rooney, who scored a hat-trick on his Manchester United bow aged only 18, ought to have established himself alongside the best players in the game - Ronaldo, of course, among them.
There was a time, says Ferdinand, when Rooney was indeed a superior player to Ronaldo during their time spent together, but claims Ronaldo's ascension to his incomparable status should not be considered any slight on the England striker.
"When Ronaldo turned up Wazza was ahead of him, but people change at different rates," Ferdinand said at the launch of his autobiography.
"He's evolved into the best player in the world but not everybody can be the best player in the world."
It may well be that Rooney and Ronaldo get to play together rather than compete against each other before the end of their respective careers, with Manchester United reported to be exploring the possibility of bringing the 29-year-old back from Real Madrid. A transfer fee of £60 million has been mooted.
It is a hypothetical deal that Rooney would surely welcome, and would result in the renewal of what was once a supremely dangerous partnership.