Barcelona's Javier Mascherano has revealed that he is "not surprised" that Kaka has returned to form at AC Milan.
The Brazilian struggled during his time in Spain with Real Madrid, but has impressed since re-joining Milan in the summer.
"I am not surprised by his improvement because I believe that football is 80% mental and 20% physical," Mascherano told ExtraTime.
"And considering that Kaka has experienced with Milan his prime as a player, it is not possible to feel better anywhere else.
"I do not know if he will return to the best Kaka, but surely we will see a great Kaka, like the one we faced [at San Siro two weeks ago]."
Barcelona welcome Milan in the Champions League on Wednesday.
