Cristiano Ronaldo recalls the time that his then-Manchester United manager Sir Alex Ferguson granted him compassionate leave during a key part of the season to visit his sick father.

The Portuguese forward, who scored 117 goals for the Red Devils between 2003 and 2009 before moving to Real Madrid, describes his old boss as "unbelievable" and says that he was his "father of football".

Watch Sir Alex Ferguson: Secrets of Success, Sunday 11 October, 22:30 BST on BBC One and the BBC Sport website.