"I am pleased to be here and I want the supporters to know that I am sure we will compete for the Scudetto," said the player to Tuttosport.
"I am a classic No 8 although I will wear the No 30 shirt at Juventus.
"In France they used to call me 'the washing machine', because I can manage tricky balls, 'cleaning' them and serving them to my teammates.
"Milan wanted me too, but Juventus were more decisive."
The former Chelsea central midfielder is expected to cost the Old Lady of Italian football a transfer fee of around £11m.