Toro Rosso have confirmed Brendon Hartley and Pierre Gasly will comprise their driver line-up for the 2018 Formula One season.
Both Hartley and Gasly have stepped into F1 in the latter stages of the current campaign.
Gasly replaced Daniil Kvyat in Malaysia - the Russian dropped by a Red Bull squad for a second straight season - while Hartley made his F1 bow in Texas after Carlos Sainz Jr's loan to Renault was brought forward.
Having scored a point in the US as a replacement for Gasly, Kvyat had retained a slim hope of returning to the team next year, but a man nicknamed 'Torpedo' by four-time world champion Sebastian Vettel looks to have run out of chances.
Gasly has long been expected to make it to F1 after an impressive junior career, he said in a statement: "I'm super happy to race for Scuderia Toro Rosso in 2018, for my first proper season in Formula 1.
"I would like to thank all the people involved, who helped me get here: Red Bull, Toro Rosso, my family and all the ones who have supported me in the lower series.
"I'm really excited and super motivated to give it my all in Abu Dhabi and the whole of next year! I just can't wait!"
Brendon got his first taste of #F1 with the Red Bull family in 2008 as a test driver. Two World Endurance Championships and a 24 Hours of Le Mans victory later, he'll complete our 2018 driver line-up!-- Toro Rosso (@ToroRossoSpy) November 16, 2017
Read his full quote on https://t.co/VypeUKqXWMpic.twitter.com/NVag1iXyhX
Hartley, who was dropped from the Red Bull junior program in 2010 but won the World Endurance Championship in 2015 and 2017, added: "It's very satisfying to have converted an opportunity that came as a surprise into a 2018 F1 drive, I couldn't be happier!
"I'd like to thank Red Bull and Toro Rosso for believing in me and giving me this second chance - dreams can come true. I'm now going to carry on working harder than ever in order to finish this busy end of season on a high and start the new year as strong as possible... Bring it!"
Toro Rosso's announcement leaves just three seats available for next year.
Sauber's vacancies are expected to be filled by Ferrari juniors Charles LeClerc and Antonio Giovinazzi, with Robert Kubica well tipped for a sensational return to Williams alongside Lance Stroll.