The 17 year-old scored in this week's Champions League win at Ferencvaros.
He told El Transistor: "He is a natural talent. He made his debut with me when he was just 16 years old in the Segunda Division, if you let him have fun, he will grow much and more surrounded by that cast of stars, I am sure that he will grow more.
"A year ago and not so long ago it was the 70th anniversary of UD Las Palmas, and Madrid, which is a great club, sent people here and we were in that moment, a club that needed money, this kid is going to mark an era in the next 10 years in European football, and I told them to look at him, but I didn't make decisions for anyone, I only felt obliged to say it for the kid and for UD Las Palmas itself because we needed the money.
"The bravest was Barça and they're the one who is going to enjoy him."