"Should I stay or should I go?"
Over the next fortnight or so ahead of the transfer window closing, Petr Cech will no doubt be running those very lyrics from The Clash's song of the same title through his mind on a daily basis.
Since his arrival from Rennes in 2004, he has been unquestionably the Chelsea No. 1. Even as he recovered from a serious head injury early into his Chelsea career there was little reason to keep him out of the team.
No goalkeeper has come close to challenging him.
Now that Thibaut Courtois is back from a three-year loan spell with Atletico Madrid, things have changed.
The gifted young upstart is Mourinho's new project, Cech being yesterday's man, a casualty in the name of evolution.
And where the 32-year-old is concerned, it's another Joe Strummer lyric that applies to Mourinho.
"If you don't want me set me free."
Regardless of everything he has achieved with the club, if Cech does ask Mourinho to leave Chelsea, he must grant him his wish.
Although the manager suggests it could be otherwise.
"I want to keep him at the club. The club wants to keep him," the Chelsea boss explained in his post-Burnley press conference.
"...I can't answer the question [if I will keep him should he ask to leave] because he didn't ask. And I hope he doesn't ask."
It may well prove a decision Mourinho doesn't want to make, but sooner or later Cech is going to demand first-team football.
And why shouldn't he?
A player of his talents is too good to warm a bench, to warm up his teammate and rival before a game.
It would be borderline degrading for him.
Imagine the scene every Saturday: Cech strips into his kit, walks out before a stadium as it slowly fills ahead of kick-off, knowing his contribution will be as a glorified cheerleader.
He's better than that. Much better.
Cech holds the all-time clean-sheets record at Chelsea for a reason. Not because he has been fortunate enough to play in the club's golden generation, nor because of the financial clout the Blues possess these days.
No, he holds such status because he is the club's greatest. Better than Fatty Foulke; better than Peter Bonetti; better than them all.
Only in the eyes of Mourinho, despite his desire to keep him, he is no longer the best. That lofty status in the eyes of the manager falls upon Courtois now.
It must have been difficult for Mourinho to choose between the pair.
On one side is a player who has achieved so much under him and has been among the world's finest for 10 years. On the other is a player primed to be the world's best and is the future of Chelsea.
For whatever reason, Mourinho eventually made his decision and he will need to live with the consequences.
Indeed, it's ironic that the very manager who gave Cech his Chelsea career by handing him his debut against Manchester United in August 2004 has all but taken it away from him by opting for Courtois.
Cech may be rewarded for his loyalty with a stint in the cup matches this year, but that will just prolong the inevitable.
In choosing Courtois, Mourinho has shown his ruthless streak can extend to his so-called allies—the players who made him at Chelsea.
He needs to remember that fact, however, and when Cech knocks on his door, request in hand, the answer must be a simple one.
If you don't want him, Jose, set him free.
*Unless otherwise noted, all quotes obtained firsthand.
Garry Hayes is Bleacher Report's lead Chelsea correspondent. Follow him on Twitter @garryhayes