Manchester United boss Erik ten Hag is happy for his players to keep moaning.
Ten Hag says it show the likes of skipper Bruno Fernandes care about the team.
The Dutchman said: "Of course it is important because it gives an expression and football is such a psychological game, win or lose.
"You have to take everything you can and use it to your advantage, so when your body language can be positive, and your expression, you use it for the good of your own team.
"What you see is the character of a player expressed in their body language and that is not a thing that you can change in a short time.
"He shows how much he wants to win so that others around him pick it up and go and fight with it."