#2 Habit of alienating certain players
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While at Manchester United, Mourinho has certainly had his fair share of dispute and strife. Luke Shaw, Paul Pogba, Andreas Pereira and most recently, Anthony Martial are just a few players who managed to get into Mourinho's bad books. Mourinho has publicly criticized Shaw multiple times for his apparent lack of effort while there have been plenty of rumours pitting Pogba against him due to his inconsistent form.
Andreas Pereira came under fire for choosing to go out of loan instead of staying and fighting for a first-team place last season and Martial has been criticized for cutting short his preseason to attend the birth of his second child.
This is a major problem not only because players like Pogba and Martial are capable of becoming world class players, but also because by singling out players one by one, Mourinho runs the risk of alienating key players and lose the support of the squad which, come midseason could wreak havoc.