Pogba's struggles in central role a problem of Mourinho's making
Claude Makelele has a lot to answer for. There were players before him whose main job was to act as a shield to the defence, but nobody in the modern era did it so well to have the role named after them.
Makelele's job was to break things up and give the ball to the players who could play, so much so that someone remarked that if Zinedine Zidane was sitting in the stands, Makelele would still try to pass the ball to him.
The notion of "defensive midfielders" is one of the great bugbears of the old-school analyst like Graeme Souness or John Giles, who were great players in the engine room with a pretty simple philosophy that midfielders were there to both attack and defend.
If your central midfield partner joined the attack, you sat back to cover the defence, and vice versa. It's not difficult but requires intelligence and discipline.
In his prime, Roy Keane found himself in scoring positions that would give Makelele a nosebleed, but Keane's generation was the last where both midfielders would be expected to do both jobs.
Instead, Makelele created an environment that allowed others to abdicate responsibility onto the security blanket beside them. It was fine if they didn't track a runner, lost possession or ran aimlessly out of position because their mate would dig them out of a hole. Which brings us to Paul Pogba.
If you were designing a footballer in a lab, it would be difficult to come up with one more physically gifted than Pogba. There's the power to bounce off anybody who tries to engage with him in terms of strength, and the speed of feet and skill to get past those who don't. He is usually brave enough to get on the ball and has the composure to know what to do with it.
What he rarely has is a sense of position to know where to be when the opposition have the ball, which makes Mourinho's decision to expect that from him all the more strange.
Pogba was dropped for Saturday's game against Huddersfield after a performance against Tottenham which was less defensively useful than a traffic cone, given that a traffic cone would at least stay in position and occasionally get in the way.
Yet, if Mourinho sees Pogba's future as that of a deep-lying midfielder alongside Nemanja Matic, at home to Huddersfield is exactly the games in which he should be playing simply because it will allow him to learn the position in a less pressurised environment where his positional mistakes won't be as exposed as they were against Spurs last week or Arsenal, who had a couple of dozen shots before Pogba was sent off with 15 minutes remaining.
The animated conversation between Mourinho and Pogba on the Wembley sideline gave an insight into the anger and frustration of the manager, but if the player isn't capable of playing in the position, then it's either Mourinho's job to teach him how to do it, or find his best role.
Pogba's most dominant display of the season came against Everton where he played as part of a midfield three alongside Ander Herrera and Matic, which off-loaded some responsibility and allowed him to be the perfect link between midfield and attack.
The arrival of Alexis Sanchez, however, means Mourinho can't afford to have Pogba, Sanchez, Romelu Lukaku and Anthony Martial all given a degree of freedom - otherwise, Matic will have to clone himself to cover them.
Martial rarely seems to fully understand the defensive demands of his manager, while Sanchez chases after possession so much that it's likely there would be a decent contest between him and his beloved dogs in the back garden to see who could pounce on a loose ball first.
Against Tottenham, Sanchez wandered central trying to win the ball back, was nutmegged by Dele Alli, which allowed for a pass to the wing where Sanchez came from before Kieran Trippier's cross was turned in to his own net by Phil Jones.
Sanchez's enthusiasm is laudable, but aimlessly running after the ball will be exposed by quality of teams which United should be measuring themselves against. Especially if those players meant to cover him don't know their job.
On Saturday, Sanchez conceded possession 32 times, which won't be punished against Huddersfield but could have given Pogba ample practice at recovering possession. Throwing someone in at the deep end and then raging at them when they can't swim isn't an ideal teaching technique.
Sanchez is brilliantly effective in making things happen but, given how often he coughs up possession, it can also mean that both teams simultaneously pose an attacking threat when he has the ball.
Most of Mourinho's best players over the years have bought into what the manager has taught them, even if it meant sacrificing what had previously been seen as a strength. Yet Mourinho has now worked with Pogba for almost 18 months but has asked him to play a particular role this season in crucial matches which has magnified his weaknesses and reduced his strengths.
Pogba should be an asset to any team looking to be successful but the fault isn't just his if he becomes a liability in a position he is patently incapable of playing.
Quite what Mourinho thinks he will teach him by dropping him against Huddersfield is anyone's guess. Whatever role he wants Pogba to eventually play, he won't learn how to do it in the dugout.