When Manchester United finally landed what could be described as a "dream signing" the hearts of United fans pounded to a discernibly faster beat, and the air tasted ever so slightly sweeter for a short while.
Then United went to Stoke City and lost.
The 2013/14 season has been a roller coaster of highs and lows for the Old Trafford faithful. Well, mainly lows.
United already have an impressive front line with Chicharito and Danny Welbeck offering diverse support to Robin van Persie and Wayne Rooney, but the issues lie in midfield.
Mata is not a cure for this illness but more like a complementary therapy, powerful enough to stave off the pain and keep fans in a better frame of mind. He is the antidote that was supposed to have been provided by Shinji Kagawa but never came.
He wont close down the gaps that opponents so easily exploit when facing the Champions, and he wont offer much in the way of protective work-rate, so what changes does Moyes need to make to accommodate the little wizard?
If Moyes decides to go down the route of 4-4-1-1 as he has done many times in the recent past, he might as well sell Mata in the next transfer window.
To get the best out of a continental player of such aplomb you need to feed him continental food and tactics.
Mata needs to play in a fluid attacking midfield where he can touch the ball aplenty and stretch an opponent's defence.
In a 4-2-3-1 Mata can work the space in front of the centre-backs, whilst still having the option to come deep and get the ball from Michael Carrick.
In any variation of a 4-4-2 this is not possible.
United's traditional formation would stifle the attacking flair that Mata possesses. Think about what Nani and Ashley Young have become: Two players known for their ability in their early years, to then becoming coached to be functional wide-men, more interested in covering the full-back and protecting their territory.
Mata cannot be this type of player for United.
He will be swallowed up as he was against Stoke, pushed out too wide to have an influence, yet not defensively sound enough to protect his defenders.
4-4-2 is dead as a viable solution for Man Utd and the sooner the manager steers his ship away from this dangerous rock formation, the better.
Mata needs freedom and when he has this, United will start beating teams again.
Interchanging with Adnan Januzaj will offer the team a wonderful balance of skill and pace, and every opponent will fear the challenge of stopping them.
Rooney must play wider
If we assume that Moyes does use 4-2-3-1 in the future, this must come with the caveat that Wayne Rooney does not always feature behind the striker.
As we know, Rooney likes to roam, so he does not just sit himself in the hole and expect others to feed him.
But there is an expectation with Rooney for him to play in the area of the park he fancies most.
With a player of Mata's class available it would be shortsighted to always play Rooney behind van Persie, forcing the Spaniard and Januzaj into the wider roles.
At times, it should be Rooney pushing towards the left, allowing Mata to slot in in-front of the opposition's penalty area.
We have seen Wayne play on the left of a 4-4-2 before to utilise his work ethic and to protect a lead but playing him on the left of a 4-2-3-1 would be a totally different affair, and one he would ultimately enjoy.
The England international will always give you a better goal return than Mata in the forward positions. He currently has 12 goals from 25 matches, per Whoscored, but the new United signing is a master of threading in a final ball.
This is something that RvP will benefit greatly from.
And as skillful as Rooney is, his first touch is not as good as Mata's, and this is vital when playing the role of trequartista.
With Rooney just to Mata's side, the Liverpudlian will also benefit greatly from his control and assists.
This is an organic process and it may not be until next season that we see Mata feature more heavily in the centre, but it is food for thought for Moyes.
Pushing Rooney out wide is not the manager sacrificing the player but more a common sense approach to using the tools at his disposal when carving his own image of an attacking and potent United team.
Moyes must sign a box-to-box midfielder
When defensive and screening matters are discussed it is easy to point the finger towards Michael Carrick and point out his excellent attributes.
But as Sergio Busquets does not carry the Barcelona midfield on his own, neither should Carrick for United.
However, the Geordie has carried the centre for the Red Devils for far too long on his own, and for this Sir Alex Ferguson must carry the blame.
United need to replace Roy Keane and not the Irishman that left United under a cloud, but the one that could maraud up and down the pitch, slaying Juventus in 1999 on his own, driving his team towards the Treble.
United need an engine but also a player with a bit of culture. If the Juan Sebastian Veron that United purchased once upon a time was available today, he would be the perfect addition right now.
There is no secret that United desire the signing of Ilkay Gundogan, as reported by Paul Hetherington from The Daily Star. He would be the correct choice for United depending on if he could prove his long-term fitness.
Gundogan would technically help Carrick control the centre of the pitch and allow Mata to move freely from midfield to attack.
His signing would be a landmark moment for Moyes and give him genuine options in a part of the field that United have suffered in for a long time.
Marouane Fellaini, Darren Fletcher and Tom Cleverley would complement Gundogan and Carrick hugely, and United's attack would benefit from the variance of support available to them. It would represent a strong and diverse unit.
And with Toni Kroos testing Bayern Munich's resolve with his wage demands, as reported by Jamie Jackson of The Guardian, Moyes could solve United's midfield conundrum with two swift world-class signings from the Bundesliga and drag his club kicking and screaming into a brand new era.
All of these potential actions would unlock Mata's potential, and United would be challenging at the top of the Premier League once more.