The Red Devils looked to van Gaal as a replacement for David Moyes, and he gave United fans a taste of what was to come with his superb management of the Netherlands at this summer's World Cup. His side made the semi-finals of the tournament off the back of his 3-4-1-2 formation, and it's one that he's used with United during pre-season so far.
7-0 and 3-2 wins over LA Galaxy and Roma have fans wondering whether the system will be used in the Premier League too, with many players seemingly suiting positions particularly well, such as Luke Shaw at left wing back and Juan Mata behind the front two.
Questions remain in the defence though, as neither Rafael nor Antonio Valencia are particularly fancied at right wing back. United have been linked with a move to sign Colombian international Juan Cuadrado from Fiorentina in recent weeks, and whilst we all assumed that he would be targeted to try and boost United's disappointing wing play, the switch to 3-4-1-2 could add more fuel to the speculation.
Cuadrado has experience of playing as a wing back or even full back down the right hand side, and reports had suggested that Barcelona were eyeing up Cuadrado as a potential replacement for Dani Alves at the Camp Nou in order to replace his attacking prowess.
What we saw in Brazil was that when Daley Blind went forward from left full back for the Netherlands, centre back Bruno Martins Indi - who can also at left back - would slide over to fill in for him, effectively creating a back four.
Now, van Gaal has both Chris Smalling and Phil Jones at his disposal. In recognising that either player could do the same job and shift over to cover for an expansive wing back when in attack, Cuadrado would still be able to go and attack without having to worry too much about his defensive duties, whilst also still being familiar with his responsibilities in terms of keeping shape.
It may cost around £30m for United to land the Colombian World Cup star, but his fit in van Gaal's 3-4-1-2 system would certainly be interesting - and potential dangerous for opposition teams trying to stop United.