The former Manchester City striker struck twice on debut yesterday.
"Mario is happy to be at Milan. I've never seen him so happy in his career and I think he can bring Italy back to the front of European football," Raiola told Calcissimo.com.
"We were not surprised by the joyful crowds who greeted him, as Mario is much loved... It's not true that he left Manchester due to a row with Roberto Mancini. As Sir Alex Ferguson said, these things happen inside a squad."