The 30-year-old made 30 appearances for Milan last season and also skippered the Italian side in the early stages of this campaign.
De Jong has not started a league game since September, however, and the midfielder has admitted that the situation is not ideal.
"Obviously I am not happy because I am not playing. But I have to wait and grab my opportunity when it comes," De Jong, who joined Milan from Manchester City in 2012, told reporters.
Eighteen-time Italian champions Milan have lost four of their first nine league games this season, with that run of form leaving them 10th in the table, seven points off leaders Roma.body check tags ::