Daniil Kvyat officially cut by Red Bull; Brendon Hartley, Pierre Gasly likely to remain at Toro Rosso

MEXICO CITY -- Red Bull has confirmed Daniil Kvyat is no longer part of its driver programme, meaning there is a "high possibility" Toro Rosso will continue with Brendon Hartley and Pierre Gasly into 2018.

Toro Rosso's driver line-up has undergone several changes at the last few races. The struggling Kvyat -- who was demoted from Red Bull to Toro Rosso in early 2016 -- lost his seat to Gasly for Malaysia and Japan, only to return in place of the Frenchman when he missed the U.S. Grand Prix to contest the Super Formula finale. That coincided with Carlos Sainz's early loan move to Renault, meaning Toro Rosso gave Hartley a shock call-up in Austin.

Kvyat's return was short-lived, however, with Toro Rosso confirming Hartley would continue alongside the returning Gasly at the Autodromo Hermanos Rodriguez this weekend. Speculation coming into the Mexican Grand Prix weekend was that Kvyat had been officially cut from the entire programme.

That news was confirmed in Friday's press conference, where Red Bull boss Christian Horner and his Toro Rosso counterpart Franz Tost faced the media.

When asked the status of Kvyat, Tost said: "He is not anymore with Red Bull and therefore he is free to do whatever he wants to do. He is no longer with Red Bull or Toro Rosso."

Speaking about the current Toro Rosso line-up, Tost added: "Both are highly-skilled drivers, fast drivers. We want to test them for the rest of the season because there's a high possibility this will be the driver line-up for 2018."

With Daniel Ricciardo not signed for another year and Sainz set to contest a season with Renault on loan, there is much uncertainty about the future of Red Bull's driver programme. Horner says Red Bull has capitalised on existing circumstances to make some evaluations for 2018 and beyond.

"The opportunities have presented themselves at Toro Rosso to test new talent," Horner said. "Danny Kvyat has had a large investment from Red Bull over the years in giving him the opportunity. He had the opportunity to step into Red Bull Racing and compete the 2015 season and the start of the 2016 season with the team. Formula One is a tough business and unfortunately Danny didn't do enough to warrant retaining that seat. But we still believed in him and we gave him a second opportunity which is very unusual in Formula One, to retain a seat with Toro Rosso.

"From there we have other juniors that we've invested in that are knocking on the door of Formula One. The current GP2 champion Pierre Gasly merited and deserved an opportunity to step into Formula One. There's very much an eye on the future and the future for next year and beyond that. I think the two drivers Franz has for next year represent two exciting prospects for Red Bull Racing further down the line."

The news means Kvyat's options for a 2018 F1 seat are limited, with Williams and Sauber the only teams with anything available.