Pique has offered support for the Brazilian, while also expressing an understanding of the supporters' whistling of him.
After the win over Rayo Vallecano, he said: "Philippe is having a good season.
"Obviously his cost was very high so that means there are more expectations of his performance level.
"It is what it is. We have to accept the reaction of the fans because they are our followers but from the inside we have to give him our support.
"We need him at his best for the end of the season and I'm sure he will be."