Juan Mata has been substituted in 53. minute of the game with Southampton, when the result was 0:0. Chelsea won that game 3:0 afterwards, but the Spaniard has clearly shown his frustration by being substituted.
Mata angrily gesticulated while sitting on the bench, as you may see on this video
Mourinho told the press that he didn’t see the incident, but he believes that Mata shown his frustration because it was 0:0 at the moment.
“He was angry because we didn’t have good result at the moment. He celebrated with the team afterwards, so I think all is ok. And if it isn’t, he can leave Chelsea in any moment. I talked to him, the board can talk to him too, I have his plans. But, if he doesn’t want to be the part of it, he can’t go. I don’t need unhappy players”, Mourinho told the press.
Mata was Chelsea’s top assistant last season, but under Mourinho he has smaller playing time.