#1 The toxic dressing room he leaves behind
One constant over the last two clubs Mourinho has coached has been the toxic nature of the dressing rooms.
He infamously had a fallout with key characters in Real Madrid's locker room, including Sergio Ramos, Iker Casillas and Cristiano Ronaldo, and reports emanated that the dressing room atmosphere was so toxic in Mourinho's final season at the helm that there were two groups of players- those who openly chastised his treatment of club legend Iker Casillas and those who were on his side.
The situation was not much different at Chelsea where just a season on from winning the league title, relationships with his players had deteriorated so badly that he said he felt 'betrayed' by his players following his sack with the club languishing around the relegation places amidst rumors that the players were intentionally putting out sub-par performances to get him out.
These were in contrast to his early coaching career where he struck such a bond with his players which usually still stuck even after his departure from the club.
There are already signs of such unrest at United, as his power tussle with Ed Woodward has had far-reaching consequences, while public criticisms of Luke Shaw, Anthony Martial and Paul Pogba sowed the seeds for disharmony.
Football is a team sport, requiring commitment from all, and it is a well-known fact that nothing is achieved in football with a divided team. Hence, it is in United's best interest to terminate Mourinho's services before they further descend into the abyss.