#5 Creating a bad atmosphere at the club
Mourinho has always been a divisive figure in his managerial career, rather like Sir Alex before him. In a sense, this has been a key ingredient of his success as sometimes it doesn't pay to be nice. However, Mourinho's negativity has at times created a toxic atmosphere at the club.
He's fallen out with plenty of United players during his time at the club, including Luke Shaw and Paul Pogba, both of whom have been publicly criticised for their attitude. In part, Mourinho has been justified in making these criticisms, but you've got to wonder about the methods of a man who has fallen out with so many people during his career.
Louis Van Gaal lost the dressing room at United (probably for boring the players so much) and Mourinho could be heading the same way. There have been signs that things just aren't right at the club and the United players never seem to play with a smile.
Mourinho might well stay beyond the summer but if he doesn't win the Premier League next season, it is a near certainty that he will be sacked. Hopefully, he can prove his critics wrong but it remains to be seen whether he can.