The summer arrival from Celta Vigo has so far been used sparingly by Pereira.
"He has a lot of quality,” Pereira said of the 21-year-old attacking midfielder.
"He's young, of course, but the time of Fer will come for sure. He's working hard, trying to be ready to help and this is the spirit.
"I have a lot of experience with talented players.
"I remember Arda Guler at 16 years old. We called him to the first team at Fenerbahce and in the first training I realised this boy is a fantastic player and he wants to play.
"This is the character of the players that have something special, every time they want to play. If they have a free-kick, they want to take it.
"At 16, we went to play in the Europa League and I remember I put him on the pitch and we got a free-kick and he got the ball.
"Every time he wanted the ball and when someone didn't pass to him he was angry with them – now he's at Real Madrid.
"Usually this is the personality of players that have self confidence, but we need to protect them.
"If they go there and they don't perform, we have the other side of the coin and they start to be anxious. They will push themselves and increase the pressure.”