Massa: Williams can't judge Kubica, Di Resta for F1 2018 in old car

Williams's shortlist for its vacancy alongside Lance Stroll next year is down to aspiring F1 returnee Kubica, current reserve driver di Resta and incumbent Massa, with Pascal Wehrlein as a long-shot candidate being advocated by the team's engine supplier Mercedes.

Di Resta and Kubica will both get tests in Williams's 2014 chassis - used for Stroll's F1 acclimatisation programme - between this weekend's Japanese Grand Prix and the next race in the United States.

But Massa argued a test in an older-specification car will not be representative.

"I think it doesn't change anything for me," said Massa, who is in his fourth season of racing for Williams.

"Williams know 100% what I can give for the team and even if you do a test with cars that are four years before, they are completely different.

"You cannot evaluate too much."

He insisted he was "pretty relaxed" about his F1 future.

"I am enjoying doing the best I can in the last races this year, and I don't know what is going to happen next year," said Massa.

I am quite keen to do another season. I think I can do it in a great way, I think I can give a lot to the team like I did already.

"But I don't decide, the team decides.

"I have given a lot to the team, and F1 as well, and if people are happy I will stay."

Massa reiterated that he would prefer to know his future before his home grand prix in Brazil next month.

Last season the Interlagos crowd celebrated Massa's career in what was expected to be his penultimate F1 race, before Williams asked him to postpone his retirement following Mercedes' move for Valtteri Bottas as Nico Rosberg's replacement.

"We don't have a deadline," said Massa.

"Definitely I think it will be good for the team, and also for myself, if we know what is going to happen before the race in Brazil.

"We'll see if that is possible, but we hope so."