The Brazilian lauded the Portuguese attacker and also reserved praise for Paolo Maldini and suggested that he has no plans to follow in the coaching footsteps of Clarence Seedorf
The Brazilian midfielder faced Messi numerous times during his time at Real Madrid before his return to San Siro last summer, where he played alongside fellow Ballon d'Or winner Ronaldo.
Zidane was involved in the set-up at the Santiago Bernabeu while Kaka was there, but not as directly with coaching until recently, but his appearances against the midfield legend earlier in his career were enough to leave a lasting impression.
"The best ones I played against were Zidane and Messi," the 31-year-old wrote in a Q&A via Milan's official Twitter page. "The best one I've played with was Cristiano Ronaldo.
"The strongest defender I've played with or against is Paolo Maldini [Kaka's former team-mate at Milan]."
Kaka also expressed his delight at playing under Clarence Seedorf, who took over from Massimiliano Allegri as Rossoneri coach in January, but played down the chances of him following in the Dutchman's footsteps when he hangs up his boots.
"It's the first time a former team-mate is now my coach," he said when asked what it's like playing under the ex-Netherlands international. "I' m so happy about it and I think Seedorf will do a great job!
"I would say no, I don't want to coach once I retire from playing, but I do not know if I will miss being part of the field of play. Who knows!"