It has been a torrid season for Williams as they sit bottom of the Constructors' Championship with just a single point, courtesy of Kubica in the chaotic German Grand Prix. Despite outscoring Russell, Kubica has struggled and will leave the team at the end of the season.
Nicholas Latifi looks the obvious choice for Williams having driven in a few FP1 sessions this year. However, Claire Williams is refusing to be drawn on their 2020 lineup and will make a decision after the Abu Dhabi Grand Prix.
"We weigh what we will do. We have a few candidates on our list that we are currently reviewing and talking to," Williams said as quoted by Speedweek.
"We take the time to think about it and make sure we make the right decision for 2020."
The favourite for the seat is Nicholas Latifi and Williams gave an insight as to what the Canadian might offer.
"Nicholas has a similar character to George, he rolls up his sleeves and does the job we ask him for.
"He's very likable, very impressive, he gets along with everyone in the team, and of course there's the advantage of knowing the team now."