Felipe Massa says his future in Formula 1 rests with Williams but is ‘relaxed’ about his contract negotiations after requesting a deadline by his home race at the Brazilian Grand Prix.

The Williams driver is battling for a 2018 race seat along with Paul di Resta and Robert Kubica, with Lance Stroll looking set to retain his spot for next year, while di Resta and Kubica will run private tests at Silverstone and the Hungaroring in a 2014-specification car to allow the British team to assess their performances.

It has been reported the private tests are solely aimed at examining Kubica’s physical condition having lost partial use of his right arm in a horrific rallying crash in 2011, while di Resta has also been given a chance to impress with the day of testing in Hungary to act as a direct comparison for the Polish driver.

Massa says he isn’t sure if the tests are confirmed but feels it won’t impact his chances of securing a 2018 race seat at Williams.

“I don’t think it changes anything for me [the Kubica test],” Massa said. “Williams knows 100% what I can give to the team. Even if you do a test with cars that are four years old they are completely different and you cannot evaluate too much so it doesn’t change anything for me.

“I am pretty relaxed so I am enjoying it and trying to do the best that I can in the last races of this year. I’m quite keen to do another season and I think I can do it in a great way. It is the team who will decide.

“We don’t have a deadline but I think it would be good for the team and for myself that we know what is going to happen before the race in Brazil to see what is possible.”

Massa had originally announced his retirement from F1 last year but was involved in a dramatic U-turn for Williams after Valtteri Bottas was called up to Mercedes as Nico Rosberg’s replacement after the reigning F1 world champion announced his shock exit from the sport.