Daniil Kvyat has joined the shortlist of drivers in the running for a Formula 1 seat with Williams in 2018 as the team continues to mull over its options for next season.

Kvyat was dropped by Toro Rosso after the Singapore Grand Prix due to poor form before returning two races later in the United States, only to then be dismissed entirely from Red Bull's programme ahead of last weekend's Mexican Grand Prix.

Kvyat confirmed over the Austin race weekend he was exploring back-up options for 2018 were he to lose his seat with Toro Rosso, with Williams holding one of the few undecided seats on the F1 grid for next year.

Williams F1 technical boss Paddy Lowe confirmed in Mexico that Kvyat had joined the shortlist of drivers in contention for a drive with the team next year as it continues to consider who will partner Lance Stroll.

"As I said in Austin, we are considering all drivers who are not contracted, but I know that is not very helpful for you," Lowe said.

"Kvyat is a very respectable driver, so he should be in the frame."

Those battling Kvyat for the seat include Robert Kubica, Paul di Resta and current Williams F1 racer Felipe Massa, whose future remains unclear despite his push for the team to make a decision prior to his home grand prix in Brazil on November 12.

"We are talking all the time to Felipe and we will see where we get with that," Lowe said.

"There are all types of scenario, but that is something I don’t want to comment on. We are managing it internally."

When asked if the situation could hurt Williams' relationship with Massa, Lowe said: "I hope not. Relationships between teams and drivers around renewals are always tense, but most of us, when we go to apply for a job, it is done in private.

"But in F1 it is a very public affair. That does make it more awkward than we would like but Felipe is a great guy and has a great relationship with Williams with respect on both sides.

"I think whatever we conclude together I think we will remain on good terms."