Robert Kubica and Sergey Sirotkin will test for Williams following the Abu Dhabi Grand Prix. Following the season finale in the desert, Pirelli will have a two-day tyre test as they evaluate and find more data on its 2018 tyres.
Kubica, who is now the outright favourite for a Williams drive in 2018 will take the car out on one day, with Sirotkin to partake in the other day. The Russian is currently Renault's reserve driver, and has had four FP1 outings so far this year.
With Felipe Massa retiring from the sport following the weekend's events in Abu Dhabi, there is high competition for his seat. Kubica is believed to be the favourite, however it is understood that Paul di Resta, Pascal Wehrlein and Daniil Kvyat are being considered.
It is not fully clear why Williams has chosen to place Sirotkin in the car for a day of testing, with some believing he too has entered the frame for a full-time seat for 2018 alongside Lance Stroll.
Bahrain International Circuit - Winter testing