He added: “Payet was, more or less, diving. Of course, he was maybe touched but not to fall like that. There is always discussion about the decisions of the referee.”
United will now look to get back to winning ways as they try and overturn a 2-0 deficit to arch-rivals Liverpool in the last-16 of the Europa League.
After that Van Gaal takes side to the Etihad for the derby against Manchester City in the Premier League.