Russian driver Sergey Sirotkin has emerged as the outright favourite to claim the last vacant seat on the F1 grid for the 2018 season.
A report from the BBC suggests that Robert Kubica was the team's preferred option until the post-season Abu Dhabi driver test, during which the drivers were pitted against one another.
Sirotkin's outright pace gave him the edge over the more experienced Kubica, effectively ending the veteran's hopes of an unlikely return to Formula 1 after a rally crash cut short his promising career in early 2011.
An announcement is expected in the next few weeks, with Sirotkin replacing Daniil Kvyat as the F1 grid's only Russian driver.
It's reported that Sirotkin brings with him financial backing of up to $15 million, and the 22-year-old will line-up alongside Canadian Lance Stroll.
In only his 2nd season, the Stroll-Sirotkin pairing is among the least experienced on the grid. Only the Toro Rosso pairing of Pierre Gasly and Brendon Hartley are less experienced with just nine grands prix starts between them.