One word that Louis van Gaal liked to use a lot was "philosophy".
There is absolutely nothing wrong with working around a football philosophy, provided it is the right one of course.
But for now, the Dutchman's attempts to lift United away from the David Moyes era continues to hit speed bumps along the way, like the abject 2-0 loss to Liverpool in last week's Europa League last-16 first leg at Anfield.
But as rumours swirl about whether Van Gaal will stay on another year or a new manager will come in (we're apparently all looking at you, Jose), United would be wise to settle on a philosophy.
If you look at the most successful club of the modern era, Barcelona, a broad philosophy has underpinned what they have been doing, regardless of the managers that have come in.
Of course it helps to have a strong academy, self-produced superstars like Lionel Messi, Andres Iniesta, Sergio Busquets and Gerard Pique as a spine, a less competitive domestic league and Olympic swimming pools full of cash to spend. But that is down to having a philosophy.
Ever since Johann Cruyff's time in charge, there have only been small tweaks to a wider project based around a broad style of play, specific manager recruitment which is often in-house and the academy.
That's in stark contrast to the lavishly wealthy Real Madrid, who have won just a fraction of the trophies won by Barcelona since 2008 and were slightly lucky to win the Champions League in 2014.
Barcelona's Lionel Messi from Argentina celebrates with Gerard Pique , center, and Sergio Busquets , right , after scoring his second goal against Hercules during their La Liga soccer match at Rico Perez stadium in Alicante Saturday, Jan. 29, 2011. (AP Photo/Alberto Saiz)
Under the presidency of the Galactico-obsessed Florentino Perez, there has been no real philosophy in terms of manager recruitment and playing style - although Jose Mourinho's counter-attacking approach did feed into Carlo Ancelotti's European Cup-winning side - bar the successes of the field with marketing and revenue generation.
Regardless of that off-field success, meddling has had more downsides than upsides as BBC' Andy West told Off The Ball after Real's thrashing at the hands of Barca earlier this season.
Barcelona have recruited individuals like Neymar and Luis Suarez and tweaked the playing style to accommodate their talents, but most importantly those players fit in to the broader remit of what Barca want to do.
In stark contrast, marketing power seems to be as important as playing roles when Real sign players in the Perez era as Radio Marca and ESPN contributor Eduardo Alvarez once explained to us on Team 33.
With Pep Guardiola arriving at Manchester City, the Sky Blues are likely to move towards a set philosophy and as football writer Miguel Delaney mused, United have been "spooked" by that development, consequently leading to those rumours about appointing Mourinho as a response.
Bayern head coach Pep Guardiola attends a news conference prior to the Champions League round of 16 second leg soccer match between Bayern Munich and Juventus Turin in Munich, Germany, Tuesday, March 15, 2016. Bayern will face Juventus on Wednesday. (AP Photo/Matthias Schrader)
But as Miguel also told Off The Ball, United are "structurally so behind the super clubs" like Barcelona and Bayern Munich who have broad philosophies and sound recruitment strategies which encompass their academies and scouting.
Man United may be wealthy but there is an inherent risk in simply throwing money at the transfer market to fix a problem or chopping and changing managers like the Roman Abramovich-backed Chelsea have done with inconsistent results.
Van Gaal may not be the long-term answer, but if they are to appoint a manager, they should perhaps look at bringing in a manager who shares some of the philosophies espoused by the Dutchman in terms of ball retention but can evolve methods with a stronger and more suitable squad to back it up.
Take Van Gaal at Bayern for example. The changes he made such as promoting Thomas Muller from the reserves and turning the club into a more possession-focused team, were followed by Juup Heynckes who kept much of that focus (only counter-attacking against Barcelona in the 2012-13 Champions League semi-finals), and that paved the way for Pep to add more elements to the type of base he can work off.
Pep might have been a perfect follow-up to United's evolutionary chain but unfortunately he's off to City which leaves United in a bit of a pickle.
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