Pascal Wehrlein has admitted he might find himself ousted by Sauber at the end of the year.
There are reports that after new team boss Frederic Vasseur swapped the team’s planned 2018 Honda deal for an extension with Ferrari, the new arrangement could see a Ferrari junior join Sauber next year.
"Obviously Ferrari want to promote their drivers," German Wehrlein, who is in Mercedes’ driver programme, said at Spa.
"They (Ferrari) have two strong drivers so it makes sense. As for my programme for 2018, I don’t know anything yet," he added, referring to Ferrari juniors Antonio Giovinazzi and Charles Leclerc.
"But I don’t have a backup plan. It’s only August. This year I signed the contract in January and the year before it was even February, but I do hope I will find out soon what is coming for me in 2018," Wehrlein said.
Asked if he would consider a stop-gap solution for 2018 as a ’reserve driver’, Wehrlein answered: "There is no point discussing that now. Talks are underway.
"There are usually different options and you always go for the best one."
Finally, Wehrlein said he is expecting Sauber to now switch focus to its 2018 car.
"It is likely that the configuration of the car will remain until the last race in Abu Dhabi," he confirmed, "but there are still things we can do with the settings."