Giuntoli says there's much more to come from the Turkey international.
He told Sky Italia: "The number 10 shirt is heavy for Juventus, we believe a lot in him and we think he has quality. But he is also a 2005, you have to know how to wait for the right times and the curves. You need patience, he is young but he is doing well."
On another youngster, Niccolo Savona, after his first call-up to the Italy team, Giuntoli added : "We are happy and proud, he is a jewel in the crown of the Juventus world and of those who raised him. He has technical, physical and also moral qualities: he is a boy from another era.
"We thank the Juve world for having raised him, but above all thanks to him, he is self-made, he has his feet on the ground and he will make people talk about him. If I think about last year his growth was fast, if I think about this year it was not."