The Pole made a fairytale return to Formula 1 after several years out of the sport following a rally crash. He has raced alongside rookie George Russell this season and although he sits above him in the Drivers' Championship due to a fortuitous point, he has been beaten by Russell for most of the season.
In the past, Nicolas Latifi has been linked with Kubica's seat as Williams seek results and the Pole admitted he doesn't know what the future holds.
“I don’t know what I will do in 2020,” Kubica dmitted at the Verva Street Racing event in Poland.
"There are no details yet. There are plans, but not everything depends on me. We’ll see how it goes. The situation is like every year — it is necessary to be patient."
Despite the uncertainty, PKN Orlen are backing their man to keep his seat for 2020.