"I'm very happy," he told the club's official website. "It's all been a bit of a whirlwind and I still can't quite believe it but I'm happy. It was pleasing when I first heard of Juventus's interest in me.
"When everything was completed last night I sat down and I couldn't believe it. As I said before, it's been a pretty hectic three or four days but I'm happy."
Juventus have the option of making the transfer permanent.