Sir Alex Ferguson and Jose Mourinho shared a close working relationship and a notable level of mutual respect for each other.
Two of the greatest managers the Premier League has seen became rivals when the Portuguese guided his Porto side to a stunning knockout of Manchester United in the Champions League in 2004.
Mourinho subsequently joined Chelsea and won two Premier League titles with the Blues before Ferguson’s United regained domestic dominance in 2006/07 – sparking a run of three titles.