The Spaniard was arguably the best player on the pitch as he scored and grabbed an assist to help Man United to a 2-1 victory in the Champions League.
It was one of Mata’s best performances in a United shirt since joining in 2014 but van Gaal still feels he can do better.
Mata has been going through a purple patch for United, scoring in three of his last four games and he has become one of United’s most consistent performers. Despite his brilliant display at Old Trafford, van Gaal expects more from his right winger.
Speaking after the game, the manager said: “I have seen Mata playing better than today. So I can say as a manager he played very well and that I agree with you, but I don’t agree with you.”
Van Gaal clearly has high expectations for Mata but it could also be a ploy to ensure the 27-year-old does not rest on his laurels. The Dutchman does have a habit of trying to make sure players do not get ahead of themselves while on a good run of form and it seems he is doing the same with Mata.
Regardless of his comments, van Gaal would be delighted if the former Valencia man can have a similar impact against Arsenal. Another goal and assist would do nicely as United look to open up a six point gap over the Gunners and remain top of the Premier League table.