The Brazilian midfielder impressed in his first start of the season as the Rossoneri recorded a creditable draw against the Blaugrana
The attacking midfielder featured from the start in a home game for the first time since rejoining the Rossoneri during the summer transfer window and Galliani was delighted with the Brazilian's display against the Liga champions.
He enthused: "I was pleased by the attacking trident. Kaka had a super match and [Valter] Birsa did well in his role and sacrificed himself well.
"It was a match of great sacrifice and I’m happy for Kaka. When he plays in this stadium, he turns it on and a lot of people are beginning to understand that he can give a lot to this team.
"It was the first time that we weren’t terrorised by Barcelona in possession and we could even have won it. You can always concede, though, and we did when we slipped up."
Galliani also briefly reacted to recent rumours that Mario Balotelli could leave the club and stressed that Milan have no intention to let go of the Italy international.
"Balotelli is going nowhere, so the fans can stay calm," he declared.
The 23-year-old's contract with Milan runs until June 2017.