The Dutch striker has made just 13 appearances this season and spent the entire 90 minutes of last night's 2-0 defeat to Bayern Munich on the bench.
Amid speculation that Newcastle are eager on his services, the 23-year-old has admitted that he is frustrated by a lack of action at the Stadion im Borussia-Park.
"I still have a week. I just want to play again. I would still love to play for Mönchengladbach, but when that's not possible I will look somewhere else. [Against Bayern] I had to warm up for the whole of the second half. It's not funny anymore," he told Goal.com.
"I still have fun during training sessions, but on matchdays it's hard for me. I spend more time warming up than actually playing. It's hard for me to be important for the team. I try to convince the coach, but I have been trying all season. I played friendlies during the winter break, but everbody gets to play in those games.
"Monchengladbach knows that some clubs are interested in me. Those clubs have been informed, but there's no offer for me yet. The coach chooses other strikers at the moment. I understand it, because the team is doing very well, but it's hard for me."
De Jong joined his German club from FC Twente in 2012.