Rashford has scored three goals in the past two games this week.
"I think he is on the way back," said Ten Hag.
"He always knew, and every player knows, when your lifestyle is not right, you can't perform. You don't get the right levels when you don't have a good and disciplined life away from Carrington."
Ten Hag continued: "In this club, you definitely need some resilience.
"No football career is only up. You always go down. You have to deal with it. He took control of it and I think he is on the way back.
"Probably he needed some help but at the end of the day, he has to do it by himself.
"He has to set his life right, his training attitude right, his match attitude right. When he sets his professionalism he will perform because he is a class player."