MEXICO CITY (AP) — Toro Rosso boss Franz Tost said Friday there's a "high possibility" that Mexican Grand Prix drivers Pierre Gasly and Brendon Hartley will make up the team's lineup for 2018.

Hartley made his Formula One debut last week at the U.S. Grand Prix in Austin and finished 13th and is the first F1 driver from New Zealand in more than 30 years. French driver Gasly made his debut in Malaysia.

"Both are high-skilled drivers, fast drivers, and we want to test them for the rest of the season because there is a high possibility that this will be the driver lineup for 2018," Tost said.

Hartley has taken a long road back to F1. Signed as a teenager to Red Bull's young driver program, he lasted only a short while before he was cut. He moved into a successful career in endurance racing where he won a world championship. He's come back to the Red Bull program a decade after he was first let go.

"He is very committed, passionate for motor sport, and I am really happy that he is back and I can tell you that if we give him a competitive car he will be there and he will also fight in Formula One for success," Tost said.

The team changes mean Russian driver Daniil Kvyat is out. Kvyat has driven with some form of the Red Bull team since 2014 but has struggled to keep his seat. In 2016, he was demoted from Red Bull to Toro Rosso to make room for Max Verstappen, who has rapidly emerged to become a star in Formula One.

Kvyat has complained about his declining position with the team. He scored points in just three races this season. In 2014, he was 19 when he set the then-record as the youngest driver in Formula One history to score points in a race. He has two career podium finishes.

"Dany Kvyat has obviously had a large investment from Red Bull over the years," Red Bull Team Principle Christian Horner said. "He had the opportunity to step into Red Bull Racing and compete in the 2015 season and the start of the 2016 season with the team. Formula One is a tough business and unfortunately Dany didn't do enough, in our opinion, to warrant retaining that seat."