Speaking at his press conference prior to United's game against Crystal Palace, Ten Hag said: "I think he always knew. Every player knows, when your lifestyle is not right you can't perform in the league we have to perform in.
"You don't get the right levels if you don't have a good and disciplined life away from Carrington.
"He needed some help, by backing him, for instance. But he has to do it himself, at the end of the day.
"He has to set his life right, his training attitude right, he has to set his match attitude right. When he sets his professionalism he will perform because he's a class player."