Pascal Wehrlein has said that he is doing all he can to stay in Formula 1 beyond 2017.
However, Germany's Bild reports that it is likely the 22-year-old will lose his seat at Sauber at the end of the year.
Sauber's owner is closely linked with Marcus Ericsson, while the other seat will go to Antonio Giovinazzi or Charles Leclerc as a result of the new Ferrari engine deal.
Wehrlein is supported by Mercedes, but there appears to be no room at a Mercedes-powered team or elsewhere for the German for 2018.
"I have scored all five points," he told Bild, "and in qualifying it is 8:2 for me against Ericsson. What more can I do?"
A return to the German touring car series DTM, where Wehrlein won the title in 2015, or Formula E are reportedly his most likely 2018 alternatives.
