Real Madrid captain Casillas' warning to Isco...

Real Madrid captain Iker Casillas has urged Isco to stay grounded.

The midfielder has been superb for Real this season and become a big fans' favourite.

Casillas regards his teammate highly, but has a warning for the youngster.

"Isco can be the next most important player who plays for this country," said Casillas.

"But he has to focus because flattery weakens you."