The Azzurri talent made the move from Villarreal on Friday for a reported â¬9m plus performance-related bonuses.
âWe are happy to have brought a great talent like Rossi back to Italy,â said Viola patron Della Valle.
âIt is not just a moment of joy for our fans, but a gift we wrapped up for all of Italian football.
âThis move is also an important one that works within our project, which continues solidly. Rossi is one of the few talents still in circulation.â