Pierre Gasly and Daniil Kvyat will race for Toro Rosso at the US Grand Prix, following Carlos Sainz's move to Renault as Jolyon Palmer's replacement.
Palmer announced after qualifying for the Japanese Grand Prix that Sunday's race at Suzuka would be his last with Renault, ending months of speculation and uncertainty over his Formula One future.
The move set off a chain reaction of announcements, as Renault confirmed that Carlos Sainz had been released by Toro Rosso to complete his move to the French manufacturer early and contest the rest of the 2017 season with the team.
It has also paved the way for Pierre Gasly to remain with Toro Rosso, meaning the Frenchman -- who finished 14th on his F1 race debut in Malaysia -- has subsequently relinquished his chance to win the Super Formula title, with the final round at Suzuka clashing with the United States Grand Prix later this month.
Daniil Kvyat, who was replaced by Gasly for Malaysia and Japan, will return to the Faenza-based outfit to compete in the race at Austin.
"I would like to thank Carlos for all his efforts over almost three Formula One seasons," Toro Rosso team principal Franz Tost said. "He always did his very best, demonstrating an excellent attitude and commitment to his work, which helped him and us to get some great results during that time. Therefore, on behalf of everyone at Toro Rosso, I wish him all the very best with his new team. We look forward to beating him on track!"
Sainz, who will be loaned to Renault from Red Bull in 2018, added: "First of all I would like to thank Toro Rosso and Red Bull for allowing me the possibility of finishing this season with Renault Sport Racing. More specifically, I really want to thank all my engineers and mechanics for their support and tremendous work throughout these years.
"Toro Rosso is made up of a fantastic group of people and I wish them only the best for the future. On my side, I will definitely do my very best in tomorrow's race... this would be the best possible send-off! Additionally, competing in these last four races with Renault gives me a good opportunity to get to know the team and the car earlier than expected. I am looking forward to start working with them."