Sergey Sirotkin has admitted he would be happy to take struggling Robert Kubica's place at Williams.

The Russian was ousted by the British team at the end of last year, but performance has slumped even more after he was replaced by Kubica.

"I am often asked about this," Sirotkin told Tass news agency when asked about the Kubica rumours.

"As a driver, I want to compete with the best drivers in the world in any car, no matter how good it is."

Actually, Sirotkin is busy with his new reserve role at Renault.

"My main task is to work on the car for 2021. The car for testing the 18 inch tyres will be ready at the end of September and I will do all the tests with this car.

"That is my key role," he added.

Sirotkin admitted that Renault is struggling to shine so far in 2019.

"Of course, with a team that has such a budget, effort and resources, much more progress and performance was expected," he said.

"I'm not going to say what exactly what goes wrong, but when there are no results or progress, the team is under pressure.

"All I can say is that I'm always happy to help."