F1 2018: Williams won't confirm driver line-up until January

Williams will not make an announcement on who will fill the sole remaining driver seat for 2018 until January.

Sergey Sirotkin is believed to be in pole position to replace the retiring Felipe Massa at Williams although the delay confirming Lance Stroll's 2018 team-mate would seemingly suggest the decision has not yet been finalised.

Robert Kubica was thought to be poised to return to F1, six years after suffering career-changing arm injuries in a crash while rallying, with the team next year.

But Sirotkin impressed during the end-of-season Abu Dhabi test when Kubica also drove Williams' 2017 car for the first time. The Russian youngster's candidature is also believed to boast significant sponsorship - worth, according to some reports, as much as £15m.

Daniil Kvyat, dropped at the end of the season by Toro Rosso, is also still in the frame to replace Massa and is understood to have driven in Williams' simulator in recent weeks.

But a Williams spokesperson said on Friday that the team "don't plan on any driver announcement until January".

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