Comment: Pogba lies at the heart of Mourinho's United future
Getting the best from the Frenchman will be crucial - but does United boss have the nerve?
Sometimes football, like real life, serves up rebukes in a teeming job lot and if anyone doubts this it is surely a good week to check with Jose Mourinho. It has been one that must have made even him feel less the leading man in his own movie - his own unforgettable self-assessment - than just another extra.
It was bad enough that it started with the sight of his £89m signing Paul Pogba slumping on the bench after a humiliatingly early withdrawal from Manchester United's nightmare performance at Newcastle. He was wearing the expression not of a sure-fire superstar but a lost and agitated boy.
That was embarrassment enough for a Mourinho last year voted by UEFA as one of the game's 10 greatest coaches.
What, after all, did it say about the nourishing of a 24-year-old who contributed superbly to the four straight Serie A titles by Juventus and is hailed in France as the player of his generation? More than anything it seemed to speak of a failure of care - and direction.
But then this was just the start of Mourinho's invitation to look in the mirror more intensely than at any point since his first brilliant assault on the peaks of football.
While Pogba wreathed in stress and confusion, two players brusquely dismissed from Chelsea by Mourinho were nothing less than lords of the Champions League action.
Mohamed Salah put in another mesmerising performance for rampant Liverpool at Porto and Kevin De Bruyne controlled Manchester City's seamless stroll in Basel as though he was merely flicking a series of switches. Their coaches Jurgen Klopp and Pep Guardiola embraced them as prospectors fondle nuggets of gold. Mourinho said, curtly, thanks but no thanks.
At 55, and for all his reputation and stockpile of trophies, including two Champions League titles, The Special One is inevitably wounded a little more each time these rejects make fresh announcements of their world-class status. He has also to accept that despite United's second place in the Premier League, and last season's League Cup and Europa League triumphs, he has rarely been under such fierce examination.
The focus is not on his career significance as a football man. That is already part of history. His aura holds but with less force than times in the past. Old Trafford natives are restless. The defeats by Tottenham, who showed a growing confidence under Mauricio Pochettino in their fine draw at Juventus, and Newcastle seemed less setbacks than statements that for the moment at least Mourinho has lost his galvanising touch.
What is clear enough is the FA Cup tie at Huddersfield and next week's visit to Seville have become a test of the manager's nerve as well as his power to motivate.
They are collisions that could well become utterly pivotal to the rest of the season - and one of the least overwhelming phases of Mourinho's career.
At the heart of his challenge is the restoration of Pogba and the true firing of Alexis Sanchez. Mourinho, the first manager to spend more than £1 billion in the transfer market is said to have wrung out £300m summer spending in exchange for signing a contract extension. But then before those cheques are signed it is hard to believe that a board which has called meetings to discuss the slippage of atmosphere and excitement on the terraces of Old Trafford will not be anxious to see more value for money in the cases of Pogba and Sanchez.
The complaint is that United are a team currently without the capacity to create any sustained belief in the certainty of their re-joining the great clubs of Europe. Against Spurs and Newcastle, Pogba wasn't the only little boy lost. The killing problem is not a shortfall of talent. The presence of such as Sanchez, Marcus Rashford, Anthony Martial, Nemanja Matic, Romelu Lukaku, Juan Mata David De Gea and, potentially above all, Pogba, weakens seriously that argument. What Mourinho needs desperately to bring in with his new signings is a sharp dose of competitive character.
United are simply without that supreme ability developed under the passionate leadership of Alex Ferguson and which has become progressively absent first under David Moyes, then Louis van Gaal and now Mourinho.
It was the belief that even on the bad days United would find a way to win, a quality which was underlined for all time when Roy Keane led the Champions League semi-final fightback against Juventus in Torino in 1999 and then United won the trophy in the Nou Camp, without the suspended Cork man, even as officials were pinning the colours of Bayern Munich to the cup.
At Porto and then Inter Milan, Mourinho cultivated that kind of determination at the highest level of the European game but at United he is yet to take anything like such a firm hold on the psychology of his team.
Pogba has become the kernel of his challenge. The Frenchman may have been hampered by a hamstring injury but it has surely not separated him from the elite of world players. He is not on trial at Old Trafford but simply in search of a clearly defined - and well-supported function.
Given that by both Juventus and France, he is a proven and much decorated player. He led France to the U-20 World Cup in 2013 and was voted the best player in the tournament. He was named best young player in the 2014 World Cup.
Juventus followers still warm themselves on the memory of his decisive play-making contribution to the victory over Real Madrid that won a place in the Champions' League final against Barcelona, his consistent strength and skill in the run of Serie A triumphs and, not least, the goal which helped beat Napoli after a long run of defeats in their ferocious stadium.
Will Mourinho re-animate the pedigree of one of the world's most gifted players?
It might well be one of the most crucial challenges he has faced in an extraordinary career. At a critical time it would also help along his rating as the ninth greatest coach of all time.