People are saying that he is carrying out a vendetta on not just Mata, but also Fernando Torres and Cesar Azpilicueta and also against an ethos that reflects the style of the previous incumbent at Stamford Bridge, Rafa Benitez.
The idea that Mourinho’s decision is motivated by personal pique and by non-footballing calculations is too simple. In my opinion, what’s happening to Mata at the moment will, in the long term, be of benefit to both the player and his country.
While many armchair followers of "highlights" football cite him as Chelsea’s best player, in terms of goals and assists, Mourinho is seeing a bigger picture.
What Mou is seeing, and saying, is that in Eden Hazard he has a player who tackles more, wins more possession, more aerial battles and more 50-50 balls. All the defensive statistics put Hazard ahead of Mata.
And here’s the point: When a manager joins a new club does he have to adapt to the players he has, or do the players have to adapt to the style of the manager?
Clearly this is not a typical Mourinho squad—rather one set up by another coach with another style in mind. The fact is that Mourinho only really knows one way to win, and that involves everybody working really hard, even without the ball, and putting in a shift at the non-glamorous end from time to time.
There is a perfect parallel to the Mata saga with Arda Turan at Atletico Madrid—in my opinion perhaps the best player in the Atletico side.
When Diego Simeone arrived, Turan did not accept that as a No. 10 he should be called upon to help out in defence from time to time. It didn’t take the astute Simeone long to remind the Turk of his obligations; Turan is now a much better player, and Atletico are flying.
Even Neymar and Lionel Messi, selectively it must be admitted, make their contribution to the collective defensive effort at Barcelona
There was much talk in the transfer window about Mata moving on—this Jacob Steinberg Guardian report linked him to Barcelona and was among the myriad articles speculating a summer exit. The fact is that, while I can confirm there were serious enquiries from Tottenham Hotspur, Paris Saint-Germain and a dozen top teams (even Barcelona considered him at one time), Mata was never for sale
Is Mourinho's treatment of Mata fair?
And, as per Yahoo!, Mourinho himself has always wanted to keep Mata. But when he does return—and return he will—it will be to play as he has been told to, not as he would prefer to. He will then become an even better player than he already quite clearly is.
That said, if Mourinho's career to date has shown us anything it’s that intrigue and politics are never far away from his Machiavellian thought processes.
The public difference with Mata is also a typical shot across the bow from Mou to his players—surely the other players must think: If he’s going to treat the best player at the club like that, how will he treat us? He tried it at Madrid with Iker Casillas and Sergio Ramos, but by that time the relationship with the dressing room had got so bad that it didn’t work.
At Chelsea his authority looks to be total, and it seems to be working. So far, he seems to be getting a reaction from the team.