Former Real boss Schuster also took a swipe at Mourinho over his lack of playing record.
"The first day he keeps everyone at bay but we'll see in two or three months. Now the first few days is very nice because people ask [questions] with a smile and do not worry you, but then when he the season starts this changes everything," Schuster told AS.
"They will be critical because they now how the game of Mourinho is. As with Pellegrini evaluation will have to be done in the end, but the season is going to be tough."
He added: "He has never played and it shows but he says the same things as any other coach, but he sounds much better and some would kill for that stuff. In truth it will be the first time we will see how great he really is."