The 20-year old French midfielder signed with the Turin outfit from Manchester United in July 2012 despite interest from some fairly big clubs in the UK and Italy.
"Sir Alex Ferguson tried to keep me at Manchester United, but he didn’t get very far," he told Sky Sport Italia.
"Since childhood I’ve always liked Juve and supported that team.
"For the French this club means a great deal, as so many French champions played in Turin, so that’s why I liked them.
"I am happy to be here and I want to win many trophies with this jersey."