It is too soon to write off Daniil Kvyat's Formula 1 career.

That is the view of Vitaly Petrov, who before Kvyat was the sport's first ever Russian driver.

Following criticism from Red Bull's driver guru Dr Helmut Marko recently, many are now predicting that Kvyat will be ousted to make room for Honda-backed Japanese driver Yuki Tsunoda.

Tsunoda has already been confirmed for Alpha Tauri's post-season young driver test.

"The season is long," Petrov told Izvestia news agency. "I think Daniil can still turn the tide. We'll have to wait a few races.

"I understand the concern of the fans about Kvyat. But as a driver who raced in Formula 1, I know how many details are hidden from the general public. We don't even know half of what is happening.

"There are a lot of things that only the team bosses or Daniil himself know about - whether the problem is himself or external factors, settings. Daniil probably cannot tell the whole truth because of his contract.

"But I noticed that Franz Tost has defended Daniil and talked about his speed," Petrov added.