Daniil Kvyat must beat Toro Rosso teammate Pierre Gasly in 2020 to secure his place in Red Bull's F1 program.
That is the view of Kvyat's Russian countryman Sergey Sirotkin, the Renault and McLaren reserve driver this year.
Kvyat claimed recently that 2019 was actually his best in Formula 1, but Sirotkin thinks his performance was more difficult to assess.
"On the one hand, he returned to F1 a more confident, sensible and mature driver," he told the Russian news agency Izvestia.
"But on the other, he did not have a clear advantage over his teammates. In the first half of the season, it was rookie Alex Albon, and in the second it can be said that he was beaten by Pierre Gasly," Sirotkin added.
"Yes, in the races he became more consistent, but the most important thing for him now is to reverse the trend against Gasly.
"We all know how fast Red Bull can change their decision, so there's a risk that they will quickly find a replacement," he said.
"But I do think he can fight on equal terms with Gasly and beat him."
Toro Rosso will be renamed Alpha Tauri for 2020.
