i think he doesn't have the quality for serie a and never.
selling him is one of the best things that moggi did.
he scored 2 goals in the match vs lazio which later was proved it did much to milan's title.
I don't think he was given a fair chance. First of all he was used as wingback and not a winger in many games, having many defencive duties. And he actually played rather well in some matches. I remember a match against Roma where he made Cafu look like a Serie C player! But the time just wasen't right i guess, but I still beleive it was a mistake selling him. And Juve didn't make that great an earning on him.