"When we’re at home we should attack, attack, attack," the 25-year-old had told reporters, candidly, after United failed to defeat Wolves in September. "That’s Old Trafford. We’re here to attack. I think teams are scared when they see Manchester United attacking and attacking. That was our mistake."
Pogba's scathing assessment of United's attacking impotence was a knife in Mourinho's bus-parking heart. He renounced him as "second captain" and told him - in private and in public - that he would not skipper the side again.
All Pogba had done in his post-match attacking football manifesto was state what Red Devils supporters are thinking. Mourinho's United attack cannot hold a candle to Manchester City, Liverpool, Chelsea or Arsenal. The Premier League's 2017-18's runners-up scrambling to stay in the top-four race, never mind the title race.
However, Mourinho has dug into his Old Trafford trenches and is braced for a bitter winter fight for survival. Pogba is collateral damage in the coach's quest to stay relevant. He's a faux fall guy for Mourinho to deflect attention from a team even he admits is frozen by fear on the pitch.
It changes nothing for a team inspired by a commanding Pogba performance to a three-goal comeback to defeat Newcastle United. He might never wear Mourinho's armband again, but Pogba remains Manchester United's de facto captain, leader and source of inspiration.
Pogba is at the epicentre of everything brilliant that comes from a team restrained by their own tactics. His elegant ball control on display as he weaved past a Young Boys defender in United's Champions League win in Switzerland. His deft pass to assist Fred in their 1-1 draw at home to Wolves was flawless.
Rewatch United's second goal against Newcastle. Pogba initiates the move with a pinpoint header into space for team-mate Anthony Martial, then ushers the defence-splitting pass with an intelligent sprint. His backwards pass that takes Mohamed Diame out the equation and gifts Martial a criminal amount of space in the opposition area to score from.
By relinquishing Pogba of United captaincy rights, Mourinho's created a hurricane out of a huff. Paris Saint-Germain would adore a midfielder with Pogba's blossoming presence, star power and performances. Ostracising a star player who fled United when he didn't feel appreciated before in 2012 is madness.
Reports of Mourinho's imminent sacking ahead of the international break proved to be nonsense, but there's no doubting his job is balanced precariously. United would struggle to sack Mourinho right now though without sending a message - players before managers - to his successor.
In reality, that isn't the full picture. Nothing Pogba said was wrong or worthy of punishment. If anything, the de facto United captain should be listened to by Mourinho.
Look what happened when the handbrake came off against Newcastle. Not every game will be played at that relentless tempo, driven on by a buoyant home crowd. It's not Mourinho's style - and that's a criticism that has been levelled at him for years. That he's strategically inflexible and his tactics are outdated.
For a man who revelled in calling Arsene Wenger a "specialist in failure", the reality is Mourinho is heading down the same path as the ex-Arsenal manager. A reliance on past achievements; stubborn, blind faith despite poor results; lurching from crisis to crisis with occasional spells of positivity that stave off the sack. They're more alike than either would ever admit.
Pogba, though, is destined for bigger things than Mourinho's mind games. He's already achieving those bigger things unshackled with France, winning the World Cup in Russia this summer. He's shown flashes of that same brilliance for United but it's drowned out by squad-wide motivational and tactical crises.
Away from his gilded United cage during the October international break, Pogba said: "You do not have to be a captain to speak. A leader is not someone who has the armband on." He was talking to L'Equipe about France, but the subtext is loud and clear.
Now the battle lines are drawn at Old Trafford, it's only a matter of time before the club have to pick between Pogba and Mourinho. A de facto captain determined to inspire change or a defiant coach desperate to avoid it.