If someone can say this kid lacks defensive contribution, then I have no idea how to describe Dybala. The kid actually has an engine and runs a lot.
Questions should be asked whether he's ready to play here, personally I'd leave him at Sass for another season or two and looked elsewhere (especially for the rumored price).
As a rotational option, I'd absolutely sign him up. We need a starting winger to replace Dybala, but we need alternatives too. Our options will be Cuadrado (hope he stays) and Berna... I don't think he is good enough for a starting position here but we need width and he can fulfill several roles. Something Allegri would like as well.