The Brazilian returned to the San Siro on a two-year deal on transfer deadline day from Real Madrid, with Allegri confident that he will be an improvement on Kevin-Prince Boateng, who left for Schalke 04.
"I'm very happy with the arrival of Kaka," LegaSerieA.it quotes Allegri as saying. "[He has] extensive experience and technique.
"He has already has enthusiasm to succeed because of the great things he has already done at Milan.
"With the departure of Boateng we needed a player in the same role and the arrival of Kaka will greatly increase the quality and technique in that area."
Allegri has been in charge at Milan since 2010.