Jamie Carragher: If Mourinho leaves United, there's no other big club who would take him on
Jose Mourinho is not just fighting to prove he is the man who can deliver the Premier League title at Manchester United. He is in the midst of a fight to preserve his position as a top level manager capable of competing in the Champions League.
If Mourinho cannot reverse the negative energy currently engulfing Old Trafford, where will he go next? There has always been a career path with Mourinho. He fulfilled his ambition to become the first manager to win the title in England, Spain and Italy and if a job has run its course at one major club there is usually a queue of European giants desperate to hire him.
Whenever he has previously become embroiled in political battles with boardrooms, although he took a hit short-term, long-term he still ended up winning.
Fall out with Chelsea at the end of his first spell at Stamford Bridge? No problem. Inter Milan are on the phone, ready to invest to dominate in Italy and win the Champions League.
Real Madrid had enough? Fine, Chelsea misses you and so does the Premier League.
Chelsea no longer wants you around? It will be okay because Ed Woodward wants a meeting.
But if Mourinho leaves United at some stage this season - and I believe they will have a new coach a year from now - what big job can he expect next? Of course he will still be one of the world's most esteemed and coveted coaches, but his next club position would have to be in the tier just below the current elite.
He would have to go somewhere seeking to rebuild, trying to catch-up, rather than one where the foundations are in place and he can target the world's most expensive players.
No other team in the Premier League's top six would pursue him. Real Madrid and Barcelona are no longer realistic options, nor Juventus. I don't believe PSG would take him at the moment. It would be a different profile of role, back to those he had at the start of his career when he was in Portugal. In some respects it would be exciting to see Jose in that kind of environment again, where I believe he would show everyone how good he is.
He has won trophies wherever he has been and there is no reason to presume that will stop. Since his return to England he has won one Premier League, two domestic cups, a European trophy, finished second in the league, and reached another major final.
Despite that, his reputation will be scarred and choices limited if the situation does not change soon at United.
That is why I see the next few months as the most challenging of his career. For all the success, one task has eluded him. He has never managed to emerge unscathed from a slump.
Wherever he has been there has been an upward trajectory - league titles or European Cups arriving - and then it rapidly deteriorates and ends. At Porto and Inter he left on a high, but everywhere else the first bad spell led to his dismissal. He could not turn it around before critics spoke of 'third season syndrome' (although most managers would love Mourinho's third seasons. At Chelsea he won the League Cup and FA Cup in his third season).
Nevertheless, Mourinho will be in new territory if he builds a title-winning team at Old Trafford from this point. As is so often the case with the greatest coaches, there comes a time when they are no longer perceived as the emerging force but those who must respond to the challengers - the fresh blood - seeking to replace them at the top.
For inspiration, the current United manager need look no further than Alex Ferguson and how he reacted when Mourinho turned up at Chelsea, and later when the billions were pumped into Manchester City.
It is generally overlooked how Ferguson went without the league title between 2003 and 2007. United won a solitary League Cup as Arsenal's 'Invincibles' and the Roman Abramovich era at Stamford Bridge posed a new threat.
Mourinho was the coach of the decade, Ferguson in danger of being representative of a bygone age, accused of 'shredding his legacy' and leading a club in disarray gauging by the tone of some articles from that time.
Ferguson emerged from those years of transition to oversee arguably his most successful period, winning five more league titles and the Champions League.
He did it by creating another young, hungry team. He spent big to do that, but cannily. Could Mourinho learn from this and act accordingly?
In terms of his style, you know what you are getting when you appoint Jose. There are three guarantees.
Firstly, he will bring trophies - which he has already delivered at United. Secondly, you get pragmatic football. Third, you will get media outbursts. This is part of the theatre, hugely entertaining when the team is winning but encouraging discontent during less successful periods. Fanning the flames is part of his character.
The problem has always been when difficulties emerge, enemies at the wrong end of the barbed comments sense an opportunity to attack - whether it is slighted agents, players or journalists. They have the capacity to undermine and feed the frenzy.
Managers such as Ferguson had the advantage of absolute power - years of success ensuring no-one could take him on and stay at the club.
Mourinho once told me after losing his job at Chelsea how he could see how management was evolving, players no longer receptive to, or tolerant of, criticism even behind closed doors. Power has eroded even for the most formidable of managers.
It may offer a clue as to the problem he has now, in a dressing room with an ego the size of Paul Pogba's, who like so many modern players (see Yaya Toure when he was at Manchester City) embarrassingly seems more interested in being loyal to his agent than the club he captains.
We know what Ferguson would do. He got rid of Pogba when he was a teenager because he knew it was more hassle than the talent was worth. He will not be surprised by the recent turn of events.
Pogba's World Cup performances have predictably become a stick with which to beat Mourinho, but they say more about the player than coach. France's style was exactly how United want to play and how the great Mourinho sides did play. Organised, athletic and so tough defensively the opponent barely lands a glove on them, but quick and incisive in possession when attacking with guaranteed goalscorers.
Pogba was fundamental to France's success playing with the midfield discipline Mourinho demands as much as Didier Deschamps. For France, Pogba deferred to his role - a high-class central midfielder with a wonderful range of passing and the capacity to burst into the penalty area.
Another player who reportedly has an issue with Mourinho is Anthony Martial. Maybe another manager would get more from him, but what have he and Pogba ever done at United to justify their fee? They cost £140 million. Where is the return on that investment? They should look at themselves.
Mourinho will not change, and given what he has achieved it is baffling anyone who appoints him thinks he should.
Mourinho has always been the manager you appoint for today, not tomorrow. So many chairman and chief executives at title challenging clubs have wanted him as manager he has never had to worry about what tomorrow will bring.
For the first time in his management career, that might be changing.