The 23-year-old says that the return of the Brazilian can help the Rossoneri reassert themselves as the dominant force in ItalyAC Milan midfielder Andrea Poli believes Kaka's return to San Siro will spark an upturn in fortunes for the club.
The Brazil international rejoined the club on a free on transfer deadline day after leaving the Rossoneri for Real Madrid in a €65 million [£56m] deal four years ago.
Milan endured a terrible start to last season but a revival saw them finish in third spot and Poli - another of the club's summer additions - believes the 31-year-old can be the catalyst behind a resurgence this term.
"He is an extraordinary footballer and I am very happy he has returned," he told the club's official website. "He has come back very hungry and I'm sure he will achieve great things here.
"It is a great privilege to be playing with him and he will be our leader."
Meanwhile, defender Philippe Mexes echoed his team-mate sentiments and backed Kaka to act as a mentor for the club's younger attacking talents.
"I think we have all the qualities to show that we can be competitive," the Frenchman added.
"Kaka is a great player and will help the attackers like [Mario] Balotelli and [Alessandro] Matri."
Milan travel to Torino in Serie A on Saturday.