1) He's taken over Chelsea's identity
Granted, some of this is down to Roman Abramovich - Chelsea's oil-rich, impetuous owner - but a genuine concern for Blues fans ought to be that Jose Mourinho has become the face of their football club.
It's hard to even describe to kids these days that Chelsea used to have an identity entirely distinct from this mercurial sulk. Remember Jimmy Grieves? I'm not sure I do anymore.
2) If he doesn't leave, some of the stars might
We've seen plenty of evidence in the last few months that 'The Special One' might have lost his special relationship with the dressing room.
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In November, we heard the stunning revelation that an unnamed member of the Chelsea squad had stated he would rather lose than win for Mourinho.
Later that same month, we witnessed Diego Costa - who netted twenty-one times for the Blues last season - hurl a bib at his manager after not being brought on during an uninspired 0-0 draw with Tottenham.
Besides these incidents, Nemanja Matic and Branislav Ivanovic - defensive players who were key to Chelsea's successful title challenge last term - seem to have disappeared and been mysteriously replaced over the summer by Joe Allen and Titus Bramble respectively.
Joking aside, star players don't become useless overnight. All this seems to point to a fundamental rupture between Mourinho and his squad in the dressing room.
3) He might just have lost it
Only the very greatest managers are capable of being successful prolifically, Sir Alex Ferguson being the obvious case-in-point. The rest of them, the mere mortals of the footballing world, have peaks and troughs of success, and there's no point clinging to memories of Mourinho's past glories.
The same logic earned Brendan Rodgers a season more than he deserved at Liverpool and gave him the opportunity to fritter away the kind of money that Jurgen Klopp would love to be given in the next transfer window. Maybe Mourinho just isn't the manager he used to be?
4) To get a manager who plays more positive football
As much as it will pain Chelsea fans, they won't have been able to resist feeling a little bit of envy for the free-flowing football of Arsene Wenger and Klopp, both of whom have successfully brushed aside Mourinho's men this season.
There was a time when it looked as if the Chelsea manager had found some kind of life-hack when it came to football. Instead of looking to control possession and press high up the field as the prevailing footballing philosophy of the past few years has suggested, he stubbornly stood by a 'defence-first' policy.
Although Mourinho's one-nils were oft-mocked by managers and pundits alike, his success absolved him from any criticism.
Now, Mourinho's philosophy seems to be crumbling before his very eyes: unable to score; unable to defend. Is it about time Chelsea hired a manager who could imitate their continental rivals?
5) For the sake of his own health
As much as we've all enjoyed it, Mourinho has started to display some rather worrying signs of late.
We remember the Special One's special wrath at the start of the season when he ranted at physio Eva Carneiro during a 2-2 draw with Swansea in August, embroiling Mourinho in a saga that has earned him numerous critics and served to heap more misery on Chelsea's worst start to the season in Premier League history.
We remember the delirium, as he dubiously declared himself delighted with his side's 0-0 draw at White Hart Lane.
We remember when things got downright weird, as Mourinho was sent to the stands against West Ham in October for allegedly trying to enter referee Jonathan Moss's dressing room at half-time.
I'm no psychologist, but all the evidence seems to suggest that by Christmas Mourinho will be delivering his delusional interviews behind sealed glass in a straitjacket.
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