Sauber are shaping up to make announcements this week in Abu Dhabi.
However, Sauber's ties to Ferrari could be getting even stronger.
It was reported recently that Sauber is under pressure to also evacuate the other seat, even though it is currently occupied by Marcus Ericsson, who is very close to the team's owners.
Yet Ferrari want their other junior, Antonio Giovinazzi, to also drive for Sauber in 2018.
"We will do the [driver] announcement, I hope, in Abu Dhabi," Sauber team boss Frederic Vasseur said.
Media sources including Speed Week and the Swiss daily Blick say that there could be another announcement in Abu Dhabi.
For months, it has been rumoured that Sauber's engines next year could be rebranded as Alfa Romeo - the Ferrari-linked luxury car brand - and Italian sources say that deal is now effectively done.