Manchester United boss Sir Alex Ferguson has warned his young players about letting success go to their heads.

Without naming Cristiano Ronaldo, Ferguson offered a timely reminder that he has been in this business for many years and has engaged in plenty of duels with egotistical footballers. He has not lost many.

"If you allow yourself to be affected by the star-status thing, then that's when your difficulties begin," said Sir Alex. "You can only achieve success when the players want to please you and not the other way around.

"Some people fall into the trap of trying to keep players happy all the time and allow powerful personalities in the dressing room to rule the roost, but that's not management.

"It doesn't matter whether you're managing East Stirling or Manchester United, you have to remember two things. Firstly, you've got to have them trying their utmost to win for you and, secondly, you've got to have control and discipline over them. Anything else and you're fighting against the wind."