Arsenal manager Arsene Wenger has identified the reason behind Kaka's failure to claim a regular starting spot for Real Madrid - because the Brazilian plays in the same team as Mesut Ozil.
Kaka has not enjoyed the best of times at the Santiago Bernabeu since his £56 million move from AC Milan in 2009, mainly down to persistent knee troubles.
Extended spells on the sidelines have also seen Kaka slide down Jose Mourinho's pecking order and, it has been reported, the former would be able to leave Madrid if a suitable offer was received.
However, the 29-year-old has been in fine fettle this season and, despite alleged interest from Arsenal, he is keen to nail down a regular staring berth.
But, says Wenger, Kaka will struggle to force himself in front of Ozil, as the young German continues to star for Los Blancos.
"Kaka is doing really well again," the Arsenal boss told Sport.
"However, I do believe that he's not at the level he had at Milan just yet. The next step for him is to get a lot of playing time again.
"The problem for Kaka is that he plays in the same team as Ozil, though, who is young and very strong. It will not be easy for Kaka to become an undisputed first-team player again.
"Everyone said that he was finished a while ago. He should be judged by his recent performances though.
"It's not easy for a player like him to find his best form again after a lengthy absence. He needs some time to get back on top."
Wenger is reported to be keen to bring Kaka to Arsenal in January, having failed to sufficiently compensate for the departures of of Cesc Fabregas and Samir Nasri.
Arsenal signed Mikel Arteta and Yossi Benayoun in the summer, but Wenger is expected to bring in more midfield reinforcements in the New Year.