Jolyon Palmer is leaving Renault with Carlos Sainz replacing him from the US GP.

Daniil Kvyat will return to a seat at Toro Rosso in Austin to race alongside Pierre Gasly after being dropped for the Malaysia-Japan double header.

Sainz had already signed a deal to race for Renault next season but the Spaniard is being released from Toro Rosso four races early as "circumstances have changed".

Palmer had previously insisted he would complete the 2017 season with Renault but announced his departure on Instagram several hours after qualifying at Suzuka.

Renault said the split was agreed by "mutual consent".

Natalie Pinkham is joined by former F1 driver John Watson and three-time Le Mans winning engineer Leena Gade to look ahead to the Japanese GP Natalie Pinkham is joined by former F1 driver John Watson and three-time Le Mans winning engineer Leena Gade to look ahead to the Japanese GP

"Tomorrow's Japanese GP will be my last race for Renault," Palmer said. "With my grid penalty I'll be starting near the back but I will be giving it my all as always.

"Thanks everyone for the support during the last two years, it means a lot!"

Tomorrow's Japanese GP will be my last race for Renault. With my grid penalty I'll be starting near the back but I will be giving it my all as always. Thanks everyone for the support during the last 2 years, it means a lot! #JP30 A post shared by Jolyon Palmer (@jolyon_palmer) on Oct 7, 2017 at 4:02am PDT

Renault boss Cyril Abiteboul paid tribute to Palmer: "I would like to thank Jolyon for his commitment to the team and his professionalism. Since Renault's return to Formula 1, Jolyon has been highly dedicated in an evolving environment. He has shown great personal qualities and we wish him all the best in his future career."

Sainz has scored all-but four of Toro Rosso's points this season and Renault will hope the highly-rated Spaniard's arrival will help them make up late ground in the Constructors' Championship. Toro Rosso are currently sixth, 10 points ahead of Renault.

"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," said Sainz. "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."

Toro Rosso boss Franz Tost thanked Sainz for his three years at the Red Bull junior team and quipped: "We look forward to beating him on track!"

With few seats available elsewhere on the 2018 grid, Sunday could be Palmer's final F1 race for at least the foreseeable future.

2018 dates and driver line-ups

The Englishman is set to start 18th at Suzuka, one place ahead of Sainz, after both received a 20-place grid penalty for engine component changes.

Palmer, a former GP2 champion, was a reserve driver with Lotus before landing a full-time race seat with the rebranded Renault in 2016. He earned a one-year extension on that deal after an improved second half to his debut campaign but he has endured a miserable 2017.

While his car has been riddled with reliability issues, he has also made several costly driver errors and he has recorded just one points finish, at the Singapore GP.

And he has failed to out-qualify team-mate Nico Hulkenberg, the German making it 14-0 in qualifying on Saturday.

Meanwhile, Sainz's early Toro Rosso exit means Gasly, who made his F1 debut in Malaysia last week, will miss out on the chance to win the Japanese Super Formula series later this month.

The Frenchman had been racing in the category this year and is half a point adrift of the championship leader but the final round clashes with the US GP.

Gasly and Kvyat are now likely to form Toro Rosso's 2018 driver line-up, although Pascal Wehrlein is considered an outside contender.

Watch the Japanese GP LIVE ONLY on Sky Sports F1 this weekend. The race from Suzuka begins at 6am on Sunday. Want to watch but not got Sky F1? Buy a NOW TV pass from £6.99!

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