Either he will make use of Mata or Mata will find himself a top club. I also think United will do things properly and approach the top managers, if they refuse they will move on (e.g. Klopp).
Mourinho will be approached to see if there is interest and if so the two will discuss things. Mourinho will think about it but likely refuse in my opinion.
Either way, he knows Mata is a top top player. He is probably better at defending than Ozil!!
I think his motives for selling Mata stemmed from a desire to move toward 4-3-3, he understood financial fairplay implications therefore sold Mata (chelsea's player of the season) to generate funds knowing what he would get for him and gave Oscar a chance probably with the view of increasing his value to somewhere similar and to sell him also because he didn't require number 10s.
Matic will be his anchor man, he isn't a top deep lying play maker like Xabi Alonso but he is a top anchor. Willian, Hazard, Salah, Schurre, these kinds of players will perform winger roles. He'll sign a striker that can hold the ball up and drop into the space between midfield and attack like Drogba did if needed, this also explains why he wanted Rooney so badly because I think he can play this role well.
Hypothetically at United his decisions would be based on the system he wanted to implement.
