The Brazilian winger was influential as a second-half substitute in Real's defeat of Betis on Thursday night, but is likely to be on the bench again for tonight's match against Getafe.
"He can be an important player," said Schuster, "but he needs to find something.
"He can be successful. He needs to find some balance in his game. He'll get his chance through the season. With Arjen Robben, we have two wingers of similar style and that will be important this season."