Do you think he can develop further? What he's capable of in your view?
From what I've seen, he tends to hold the ball a bit in certain situations but that could be because of the burden to create offence on Fiorentina or the U21s. He will improve there surely with us.
Physically, you can probably project a slight improvement as he approaches 25 or 26.
For me, he's not a match winner on his own right now. But he can do so many things on the pitch that I find it hard to believe he won't contribute. If he's on the right then he has the threat to cut in with his good left foot. If he's on the left, he he can pick Higuain/Dybala. If he's in the centre, he still has enough technique and strength to receive passes and break the defensive midfielders. Even for the U21s, he was playing as a target man and brought balls down in the air.
I wouldn't be shocked to see him play as a CM a little bit this year.
He's more of a player that augments the star players in my eyes. I don't think he's this special, new, Italian #10 Fantasista but overall he will be effective. If the ball falls to him in the box after Dybala does all the work, he can put it in the net. If Higuain has an opening, he can get the ball to him. If he has to track back to cover Alex Sandro, he can get back.
But like I said, he has just enough quality that sometimes he can just put the ball on his left foot and pick the corner.