Mourinho has never hidden his distain for some of his managerial rivals, with Arsenal’s Arsene Wenger and Aston Villa’s Paul Lambert crossing swords with the Chelsea boss already this season, and the prospect of a crucial clash with a team capable of ending his side’s unbeaten start would usually bring out the antagonist in the Portuguese coach.
Yet there should be a refreshing lack of animosity on the sidelines at Old Trafford this weekend, however heated the action becomes on the pitch, because Mourinho and United manager van Gaal have a bond that dates back 17 years to the day their paths first crossed at Barcelona.
Mourinho, then labouring in anonymity as a translator and assistant to Barcelona manager Bobby Robson, was kept on by van Gaal when he took over at the Nou Camp and earned the trust of his new boss to such an extent that he was allowed to take training sessions and give team-talks.
Van Gaal saw a kindred spirit in Mourinho, who like the Dutchman is an obsessive workaholic who had trained as a PE teacher, and the two men lived only 15 metres from each other in an apartment block, often meeting around their dining tables to talk football.
The partnership lasted until Mourinho left to start his managerial career with Benfica in 2000 and the ties between the pair remain strong, with Mourinho paying tribute to his mentor when asked about van Gaal’s influence on him.
“As a young coach to be working with Louis at a club like Barcelona was very important,” Mourinho said.
“Everybody knows the respect I have for him. I never hide the respect, the relationship and the fact he was an important influence in my career.
“He knows what I feel about him. The world knows, because I never hide. What can I add?”