Williams will run Sergey Sirotkin next week in Abu Dhabi at the team's post-race Pirelli test where Robert Kubica will also drive the team's 2017-spec car.
The 22-year-old Russia, who ran this year in four Friday free practice sessions for Renault, will take to the track in the team's FW40 on the second day of the two-day test while Kubica will run on the morning of the first day, with Lance Stroll taking over in the afternoon.
The Polish driver is the lead contender for Williams' second seat alongside Lance Stroll next year, with Paul di Resta, Pascal Wehrlein and Dany Kvyat also under consideration for the drive.
It's unknown at this stage if Sirotkin's presence behind the wheel of the Williams is a one-off opportunity or if the Russian hopeful is a last-minute addition to the team's short-list for 2018.
German broadcaster RTL GP announced earlier this week that Kubica had signed a two-year contract with Williams, but the British team denied it had concluded a deal with the Pole.
Williams said in a statement yesterday that "conversations are ongoing" with Kubica, with no announcement planned for this weekend.
Gallery: The beautiful wives and girlfriends of F1 drivers
Keep up to date with all the F1 news via Facebook and Twitter
Charles Leclerc believes Formula 1's new-era machinery has forced him to rethink one of the…
Formula 1's teams and drivers regroup this weekend surrounded by the majesty of the Ardennes…
Max Verstappen has once again refused to reveal his hand on his Formula 1 future,…
Aston Martin is facing a race against time at Spa-Francorchamps, with the team's ambitious push…
Red Bull has opted for caution over innovation ahead of this weekend’s Belgian Grand Prix…
Max Verstappen has made a significant move away from the Formula 1 cockpit by welcoming…