Louis van Gaal is a man who has won silverware in his first seasons in charge of European giants such as Ajax, Barcelona and Bayern Munich.
Manchester United will not be added to that list however, after a disappointing elimination from the FA Cup at home to Arsenal on Monday night.
Van Gaal now has just ten games left of his first season in charge in which he will hope to land a top four place, in the hope of avoiding his debut season in English football being labelled a disaster.
United fans had hoped for a title challenge after a summer of spending, or a domestic trophy at least.
But Monday night’s result has put an end to those hopes, and now the inquest into how they suffered a first defeat to Arsenal at Old Trafford in eight years is underway.
Here we have identified five reasons as to why it may have gone wrong for van Gaal and his side on Monday night.
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Click on Louis van Gaal to reveal 5 reasons why Man United lost to Arsenal on Monday night

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Individual mistakes

Playing Arsenal in an FA Cup quarter final is difficult enough without giving away goals for free.
There will be questions asked as to how Alex Oxlade-Chamberlain was allowed to dance past three challenges on the edge of the box before teeing up an unmarked Nacho Monreal for the opener, whilst the nature of Danny Welbeck’s winner was comical for anyone who is not a United fan.
Antonio Valencia’s short backpass was capitalised on by the former United striker – who to rub salt into the wound, had never scored an FA Cup goal at Old Trafford during his Manchester United career.
Simple enough, but such a poor error at a key time in the game is what ultimatley cost United the chance of walking out at Wembley.
No Juan Mata?

The mystery of Juan Mata at Manchester United rumbles on.
The Spaniard finds himself out of the starting XI at the moment, with van Gaal favouring Maraoune Fellaini in that ‘number 10’ role.
Whilst that is strange enough, the former Chelsea man was not even introduced from the bench as United went in search of an equaliser.
Bizarre when you consider his record of goals and assists in English football. United fans must surely be concerned for the future of their £38million playmaker.
Di Maria’s red card

Attempting to come back from a goal down in an FA Cup quarter final is difficult in itself – whilst a red card to arguably your most dangerous player in such a situation makes it all the more unlikely.
United still had time to save their FA Cup dream when the Argentine was shown two yellow cards in a matter of seconds – the first of which for diving, and the second for pulling the back of referee Michael Oliver’s shirt.
Di Maria has not been at his best for some time, but he provided Wayne Rooney with an assist in the first half and is one of those players capable of producing a moment of magic out of nothing.
The manner of his red card rather summed up his debut season in English football – disappointing.
Falcao an unused sub

12 months ago, a scenario in which Radamel Falcao would remain as an unused substitute whilst his team battled to come from a goal down would have seemed almost impossible.
Yet that was the situation Manchester United found themselves in at Old Trafford last night, and the Colombian was not called upon – perhaps the clearest indication yet that Falcao does not have a long term future at the club.
Van Gaal refused to throw on a striker who despite having often struggled this season, has been one of the most respected strikers in world football over the past five years.
Whether Falcao would have made the required impact, we will never know. But van Gaal’s lack of desire to gamble when chasing the game ultimatley proved costly.
Januzaj diving when in good positions

And the decision not to call on Falcao was compounded, when the man brought on ahead of him – Adnan Januzaj – was shown a yellow card for a blatent dive in the penalty area when well placed.
The Belgian had the opportunity to go on and create an equalising goal, but opted to try and con referee Michael Oliver instead.
His booking also meant Januzaj now has more yellow cards for diving in his Manchester United career (5), than goals (4).







