Jose Mourinho will look to trim his squad at the end of the season if he remains in charge at the Santiago Bernabeu, with several players being allowed to leave.
As well as Kaka, other players who could be on their way out are Ricardo Carvalho, Raul Albiol, Lassana Diara and Hamit Altintop, while Gonzalo Higuain has recently been linked with a move away from Madrid.
Kaka, who cost a then-world record fee of £56m when he moved to Madrid from AC Milan in 2009, has endured an injury-plagued spell in the Spanish capital.
A Kaka exit would be a surprise to many after Mourinho highlighted that he was keen to help the Brazilian rediscover his Milan form, according to Spanish daily AS.
Real Madrid currently top La Liga and have a seven-point lead over Barcelona with four games to go.