Marcelino introduced Torres to first team football at VCF before the midfielder's summer switch to City.
He told Onda Cero: "I think he set the record for the youngest player in history of Valencia to play 50 games. You could see it, but he needed time because Valencia at that time was fighting for the Champions League and a participation in a Champions team is not the same as being in the middle of the table.
"It was clear that Ferran had a stunning conditions, is a hardworking guy with a very good head, ambitious. Very ambitious which is a plus for the great talent you have and needed. Training because being 17 years old physically and mentally is not easy. But no one at Valencia doubted his ability and that sooner or later he was going to show that he is a first-rate footballer."