Three is the tragic number.
Jose Mourinho started the game by walking half a mile to the stadium. He ended it looking like he was angrily hailing someone else's Uber. With two minutes of injury time to go - and Manchester United still only a goal behind - the Portuguese was more interested in goading the visiting fans than urging his team forward.
It was meant as a defiant reminder of his prowess. A reference to the treble he won at Inter Milan. But there was something incredibly tragic about a man who once roared down the very same touchline as Porto coach, euphoric and utterly lost in a winning moment, now flailing around digits to signify his glorious past.
It hardly needs saying but Mourinho is now a parody of himself, and his trident salute is becoming something of a grim signature. You can imagine him on a nightclub stage, alongside Howard from the Halifax ads and Bubble from Big Brother, looking forlorn and out of place as the crowd demands he 'do the fingers'.
It's the same sorrowful trick he pulled at Stamford Bridge on the weekend, to remind them too of what he once was. On that occasion there was at least a faint hint of solidarity, as it led United fans - and even some Chelsea supporters - to nod in agreement that he was perhaps deserving of a smidgen more respect.
But how can you respect a man who no longer seems to fully respect himself, or at least the current version of himself. To hint to the past in mime form once looks like a spontaneous act of riposte. But to repeat the act again and again hints at a once proud man who is out of ideas. It's more arthritic than heroic.
With his dark suit and turtle-neck jumper, Mourinho looked every inch the Apple guru, ready to unveil his brand new invention onto an eager public. The stage was set for this great mastermind to wow and amaze the world once more. But with three tragic fingers in the air, all he was presenting was his own obsolescence.
