AC Milan midfielder Kaka is suffering from fresh knee concerns.

Kaka has been ruled out of Milan's Russian Railways Cup match with Chelsea due to suspected tendonitis.

Milan released an official statement last night confirming he would be undergoing a specialist training schedule over the next few days due to "a persistent inflammation of the left knee."

This is causing concern because that was the knee that required surgery at the end of last season.

O Globo says it is tendonitis and Kaka must rest for at least two weeks in order to fully recover.