LONDON: Jose Mourinho is 53. Jurgen Klopp is 49, Antonio Conte is 47, Pep Guardiola is 45, Mauricio Pochettino? Just 44. Does the fact that Mourinho is already in his 50s matter?
Mourinho very much portrays himself - with justification - as the man who defies history, flouts convention. But football has few managers who go to a big club, one having to be rebuilt to be made competitive again, in their 50s and enjoy fabulous success.
OK, Claudio Ranieri is 64 and won the Premier League title last season in his first campaign at Leicester City. But Leicester did not need a rebuild. They just needed a shrewd Tinkerman. And it was, by common consent, a strange old season.
Ronald Koeman is the same age as Mourinho and has a big job on his hands to make Everton competitive again - and has made a fine start - but he is not under the same level of scrutiny or pressure.
This is not ageist. It is certainly not anti-Mourinho. United are not in crisis. It is not, after three successive defeats, asking the question as to whether - to put it bluntly - he is a bit of a busted flush even if, despite the wave of early-season excitement, there remain serious concerns about his Chelsea implosion. Was that a blip or the start of a trend?
Instead, it is simply to ask whether it is possible for a manager in his 50s to go to a club like United and succeed. And, especially, whether, in fact, football and management have moved on in a way that, maybe, Mourinho has not. Of course, he returned to Chelsea and won the title - in his second season - aged 52 but the club he found was not vastly different from the one he had left behind. Chelsea had not moved too far away from the foundations he had laid before he was first sacked in 2007. The template was still there.
Maybe, though, Mourinho is the same but not the same. His methods have not evolved that much in recent years and, unlike Sir Alex Ferguson - the man he dreams of emulating - he has not refreshed and changed his backroom staff in search of new ideas, new faces, new energy, new impetus. It is largely the same loyal personnel: Rui Faria, Silvino Louro and so on, who have followed this serial achiever across Europe.
Except Mourinho is not quite the trophy-gatherer he once was, either. Between 2002 and 2010, he collected six league titles and two Champions Leagues. Since then, he has won two league titles - respectable enough in a market where there is only one winner - but has left the two clubs he has managed to those triumphs in difficult circumstances.
Mourinho may well still be a great coach - and few would sensibly argue otherwise - but is he still the Special One? It is surprising that he has not adapted more throughout the years and, specifically, has not adapted his spiky management in a game that has changed. Players need to be treated more subtly.
The early weeks of Mourinho at United were full of stories of how he had brought a lightness and belief back to a club straitjacketed by the claustrophobic management of Louis van Gaal, but there have been glimpses in the past week that he still has the style of management that can cause unnecessary conflict.
Interestingly, he has - again - turned it on to the younger players. After the defeat by Manchester City, there was the claim that the game was too big for some of his players with the finger pointed - by implication - at Jesse Lingard and new signing Henrikh Mkhitarayan. After the defeat by Watford on Sunday, he stoked that further with the suggestion that players lacked mental strength, with the focus on "the left-back", ie 21-year-old Luke Shaw.
Against Feyenoord in the Europa League last midweek, there was the archetypal Mourinho attempt to display his displeasure in a triple substitution that always looks like it says more about the manager than the players.
So, United knew what they were getting. A manager in his 50s such as Mourinho is not fundamentally going to change his ways, although he has to be smart enough to adapt and there have been glimpses in the last few games that, when the pressure is on, he reverts to default mode.
There was logic in Mourinho's appointment and there are signs that it will work out and he will be a success. Either way, it is far too early to call it, and certainly far too early to say it will fail. United reasoned they needed a big manager, a big personality, with a big profile, a man who could carry the club - they thought it was Van Gaal - especially as across the city, City had signed up Guardiola.
But while there is a freshness, a burst of new ideas and energy to Guardiola's approach at City - just as there is with Klopp at Liverpool and with what Pochettino has done at Tottenham Hotspur - we are still waiting for that with Mourinho at United. A swagger has returned, although it has faltered of late, but a swagger and a barrel-load of big signings are not enough. Where is Mourinho's big idea? The big bang really to get United moving once more?
Mourinho has 15 years of, mostly, astonishing success behind him in a remarkable career spread across four leagues. Few will top that or come close to maximising resources in the way he has. But there has been a sense for some time that football has moved on while, maybe, Mourinho has not. It is just a theory and a man of his talent, charisma and belief should demolish it. But it is a theory that will gather momentum unless that happens quickly.