Robert Kubica has emerged as a front-runner for a seat at Williams in 2018 as the Grove-based outfit narrows its choice down to three drivers.
The Polish driver is attempting a sensational F1 comeback after his career was abruptly halted in 2011 following a serious rally crash.
Multiple test outings with Renault validated his ability to competitively drive an F1 car, but Carlos Sainz's move from Toro Rosso to the French outfit next season squashed Kubica's hopes of joining the team.
Williams' interest in Kubica enticed the British team to put the Pole in its simulator for an evaluation. But Kubica could also test a 2014-spec Williams for further evaluation in the coming weeks, likely in Brazil, when it runs Lance Stroll during the Canadian's ongoing private test program.
In a bid to boost his comeback endeavors, Kubica recently joined forces with Nico Rosberg's management company, but the Pole will still be up against a couple of worthy contenders for the coveted seat.
Ultimately, Williams' choice for 2018 should boil down to Felipe Massa, Robert Kubica and Paul di Resta, who replaced Massa in Hungary when the Brazilian fell ill.
Jolyon Palmer is not believed to be considered a serious contender for a seat at Williams alongside Lance Stroll next season.