Brendon Hartley will continue with Toro Rosso at the Mexican Grand Prix, where Daniil Kvyat will once again give up his seat to the returning Pierre Gasly.
Toro Rosso's driver line-up has changed on numerous occasions in recent weeks, a result of uncertainty over its team for 2018 and Carlos Sainz's early departure to Renault. Kvyat's poor form had seen him dropped ahead of the Malaysia-Japan double header for Gasly, who won last year's GP2 championship.
When Sainz went to Renault ahead of the U.S. Grand Prix, Kvyat returned but Gasly was unavailable as he was due to contest the Super Formula finale. Gasly's other commitment -- which ended up being cancelled due to a typhoon -- prompted Toro Rosso to make a shock call-up for former Red Bull junior Hartley, his first drive in an open wheel car for half a decade.
Hartley was hit with a Toro Rosso engine penalty before turning a wheel of his car, but turned in a solid race drive to 13th on his debut. Kvyat marked his return with a good drive to 10th but it appears Toro Rosso is keen to give Hartley another chance to prove his potential for 2018.
On Monday, the team confirmed its line-up with a simple press release which did not state whether the Hartley-Gasly tandem will continue beyond Mexico City or what the status of Kvyat's future will be. It means Toro Rosso will have had three different line-ups (Sainz-Gasly, Hartley-Kvyat, Hartley-Gasly) at the last three races.