There are those who would immediately point out that of the five games Carrick have started, two have been in the EFL Cup, one the Charity Shield and one in the Europa League against the weakest side in the competition. Though another way of looking at it was that those victories – two of them over the champions, one against Manchester City - have included the three matches in which United have been most persuasive this season. And that is surely no coincidence.

Because this is the thing about Michael Carrick: he makes the players around him better. Not possessed of the quickest turn of pace himself, he has an ability to pick out a pass which unleashes the pace of his team-mates. With Carrick in the side, firing out his trademark quick-fire passes, everyone moves quicker. There is no Louis Van Gaal-style sideways obsession with him. He gets the ball moving. And has he does so, he gets his team-mates moving.

Too often this season United’s problems have stemmed from a lack of pace. Yet, in the likes of Marcus Rashford, Anthony Martial, Luke Shaw, Antonio Valencia and Jesse Lingard they have speed to burn. Too often, however, that pace has not been exploited. But it has when Carrick has played. His zippy interventions put his colleagues on their toes.

And it is not just the quick players who play better with Carrick behind them. Juan Mata is a far more productive number ten when he is getting sharp passes to feet from those behind him. With early delivery, he can all the better use his intelligence to create defence splitting opportunities. Carrick makes him better.

Yet Carrick remains on the bench. When United needed to find someone to open up an obdurate Burnley defence on Saturday, Mourinho called on Wayne Rooney, Marouane Fellaini and Memphis Depay, three players you didn’t really have to be Einstein to appreciate are not on the top of their form (actually two of them possibly are, but no United team worthy of the name should ever include Fellaini or Depay). Carrick sat rooted to his seat, watching chances disappear for want of intelligent delivery.

For sure there are issues with Carrick. He is 35, so there is little point trying to build a new side around him. But then so is Zlatan Ibrahimovic and he plays every minute of important games for Mourinho. The manager clearly believes he has something to offer in the here and now. Albeit that appears to be not much more than allowing Tom Heaton the Burnley keeper the opportunity to show he is the next England goalkeeper.

But the here and now is vital. And Carrick should surely be used more than he is. Given what a lift he brings to the side, five starts is paltry to the point of self-destructive.

If you don’t believe me, watch him play on his next rare appearance in the United first team. Chances are it will be in Turkey on Thursday. See him against Fenerbahce and you will see the point. I believe United with him in the side will move quicker, they will create better chances, they will look more coherent, more persuasive, more positive. But then, what do I know? I’m just an Einstein.