The Brazilian striker, who nearly joined AC Milan in the summer, has so far this season scored 10 goals.
Ranieri said: “I made the club spend a lot of money, so I knew Amauri would score so regularly!
“He was the player I was missing, someone who would help hold up the play and fight for the ball. Amauri arrived at the right time, he had his experience around Serie A and is now ready for Juventus.”
