Toro Rosso have confirmed Pierre Gasly and Brendon Hartley will be their drivers for 2018.

The announcement leaves just Sauber and Williams to name their line-up for next season.

Gasly and Hartley had been expected to retain their seats for 2018, having been drafted into Toro Rosso following Carlos Sainz's departure to Renault and Daniil Kvyat's exit from the Red Bull driver programme.

2016 GP2 champion Gasly made his debut for the Faenza-based team at the Malaysia GP, while World Endurance Championship champion Hartley made his F1 grand prix bow at the US GP.

"We're really happy to have Pierre and Brendon confirmed so early by Red Bull as our drivers for 2018," said Toro Rosso team boss Franz Tost.

A proven World Champion racer and a rapid young rookie? Sounds like the perfect driver pairing to us! We can’t wait to start working with @BrendonHartley, @PierreGASLY and the whole @ToroRossoSpy team in 2018 👏💪 https://t.co/VJ9JZYcjfv — Honda Racing F1 (@HondaRacingF1) November 16, 2017

"During this last part of the year they've shown that they're ready for Formula 1, getting to grips with the car quickly, showing good performances and always demonstrating to be prepared for the challenge.

"We have been truly impressed by both their steep learning curves.

"I'm sure they will keep pushing hard and fight for strong results, together with the team."

The partnership of Gasly and Hartley was the fourth different line-up Toro Rosso fielded in 2017.

Toro Rosso's driver line-up in 2017 Australia - Singapore Carlos Sainz Daniil Kvyat Malyasia & Japan GPs Carlos Sainz Pierre Gasly US GP Daniil Kvyat Brendon Hartley Mexico - Abu Dhabi Brendon Hartley Pierre Gasly

Having started the season with Kvyat and Sainz, the Russian was replaced by Gasly in Malaysia and Japan.

Kvyat returned at the US GP following Sainz's early move to Renault, while Hartley was drafted in when Gasly was due to compete in the Super Formula season finale - an event which was then cancelled due to bad weather.

Gasly's return saw Kvyat dropped permanently, and his partnership with Hartley will also be the fifth different driver line-up to start a season with Toro Rosso in the past six years.

"It's very satisfying to have converted an opportunity that came as a surprise into a 2018 F1 drive, I couldn't be happier," said Hartley.

"I'd like to thank Red Bull and Toro Rosso for believing in me and giving me this second chance - dreams can come true."

Gasly added: "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!"

Toro Rosso's line-up at start of season 2013 Daniel Ricciardo Jean-Eric Vergne 2014 Daniil Kvyat Jean-Eric Vergne 2015 Max Verstappen Carlos Sainz 2016 Max Verstappen Carlos Sainz 2017 Carlos Sainz Daniil Kvyat 2018 Brendon Hartley Pierre Gasly

Comment below to get involved in the debate, but please adhere to our House Rules. If you wish to report any comment, simply click on the down arrow next to the offending comment and click 'Report'.