Bernie Ecclestone says financial woes for the Nurburging and a lack of a deal with Hockenheim could put an end to this year's German GP.
Although the Nurburging was down to host this year's edition of the German GP, the circuit's on-going woes meant Hockenheim looked set for back-to-back events.
However, even that is in doubt as a contract has yet to be agreed.
Asked by Sky Sports News HQ if a deal was in place, Ecclestone said: "Not really."
The F1 supremo is keen to see Germany remain on the calendar but concedes that if the money is not there, there is nothing he can do about it.
He added: "We would do everything to stop them fading away, but in the end the only reason the race won't happen is because they can't afford to run the race."
Finances for both German venues have taken a hit in recent years partly to dwindling spectator numbers.
Ecclestone believes that is largely because Germany's seven-time World Champion is no longer in the sport
"Honestly I don't know [why the event is struggling], it surprises me," he said.
"Maybe it's a little bit that the German people were very used to and supported Michael and miss Michael when he wasn't racing any longer."