Robert Kubica will test for Williams in Abu Dhabi after this weekend's season-closing grand prix.
The test is effectively the final step in an evaluation process to see if the Pole can return to Formula 1 in 2018 after seven years away.
Williams will also assess Renault reserve driver Sergey Sirotkin.
The Russian has emerged as a candidate along with Daniil Kvyat, Pascal Wehrlein and Paul Di Resta, although Kubica remains their first choice.
The team are keen to sign a proven talent alongside Stroll, who has generally struggled to match veteran Felipe Massa in his debut season this year, other than a couple of impressive drives in the Azerbaijan and Italian Grands Prix.
Massa is retiring from the sport after this weekend's race.
Kubica has not raced in F1 since 2010 but has done a...
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