Williams driver Felipe Massa is keen to continue in Formula 1 next season, saying he sees "no reason" to end his grand prix racing career.
The 36-year-old had initially retired from F1 at the end of 2016, but agreed to a return to Williams after Valtteri Bottas was signed by Mercedes.
Massa, who made his debut in 2002 and has started 260 grands prix, believes he is still improving as a driver and will continue in F1 if he has the right opportunity.
Williams has yet to decide on who will partner Lance Stroll in 2018, with Massa among the contenders to stay on for a fifth season with the team.
When asked if him staying on was dependent on there being a good opportunity, Massa told Motorsport.com: "Sure, yes. I’m really in good shape, the way I’m driving, the way I understand the car and everything.
“I have no reason not to stay in F1, but we’ll see what’s going to happen.
Williams chief technical officer Paddy Lowe is impressed by Massa’s approach, and believes the Brazilian still has the ability to fight for the world championship given the right car.
“Felipe is world champion material, we saw that from the season he was briefly world champion ,” Lowe told Motorsport.com.
“He is clearly very talented and it’s a great pleasure to work with him and find out how he works.
“He’s a fantastic guy to work with: enthusiastic, friendly, very supportive of Lance and the learning that Lance needs to go through.
“He’s fun to work with and a very stable and dependable guy to have on the other side of the garage. I think if we could give Felipe the right car, he could go and get the job done.”
Massa believes that his short-lived retirement has allowed him to return to F1 in a more relaxed frame of mind.
He has taken two sixth-place finishes this year, in Australia and Bahrain, and was on course to finish on the podium – and might even have been able to fight for victory – in Azerbaijan before retiring with a broken damper.
“I’m racing in a much more relaxed way and I’m happy with what I do in the car,” said Massa. “Unfortunately, I was a little bit unlucky in a few races, but I’m enjoying it.
“Not thinking about some other things that are sometimes inside your job just makes you more relaxed, doing what I like to do, enjoying it and no pressure.”