Paul di Resta remains a leading contender to drive for Williams next season alongside Lance Stroll, as the final pieces in the 2018 driver market prepare to fall into place.
Di Resta, currently the team's reserve driver, is highly respected by Williams and impressed when he replaced the unwell Felipe Massa at the Hungarian GP in July.
A decision by Williams on their 2018 driver line-up has yet to be taken and Massa's retention for a fifth season at Grove remains a possibility.
But if the Brazilian, who retired from F1 a year ago only to return to Williams when Valtteri Bottas departed to replace Nico Rosberg at Mercedes, does finish his F1 career in November then either Di Resta or Robert Kubica are poised replace the veteran.
Kubica suffered career-changing arm injuries in 2012 but tested three times this summer for Renault before being overlooked in favour of Carlos Sainz. Doubts persist about the viability about Kubica making a full-time return to the sport and Renault admitted there were still unresolved questions about the 31-year-old's candidature even after he ran the equivalent of two race distances in August's test at the Hungaroring.
No such question marks are affixed to Di Resta. The 31-year-old became Williams' reserve driver in 2016 and qualified within a second of Stroll in Budapest following his last-minute call-up despite having never driven the car prior to qualifying.
"I think he's done his reputation no end of good this weekend," Williams technical chief Paddy Lowe said. "Paul did an absolutely terrific job, as I think everyone recognised."
The Scot also drove for Force India for three seasons between 2011 and 2013.
A strong end to the season may also bring Jolyon Palmer into contention to replace Massa but the prospect of a second Brit joining Lewis Hamilton on the grid next year appears to rest on the anticipated choice of Di Resta or Kubica.
Due to his ties to Mercedes, who are Williams' engine providers, Pascal Wehrlein has also been linked with the anticipated vacancy. But the 22-year-old's age may have already annulled his candidature as Martini, Williams' principal sponsors, are understood to oppose a driver under the age of 25 partnering teenager Stroll next year.