Felipe Massa has confirmed the paddock perception that Williams look set to be 'best of the rest' behind Formula 1's top three teams early in 2017.
Many observers believe that Mercedes, Ferrari and Red Bull are clearly leading the field, with a gap then to the British team.
Brazilian driver Massa told Globo: "I think testing for us was good.
"In fact after 2016 and how it went for Williams, I had a big concern about how it will be in 2017 especially with the big change in regulations.
"So I was not 100% calm, especially because I decided last September that I would stop racing and so I was not very interested about how the car would be this year.
"I think Barcelona helped me to get an idea that we definitely have a competitive car. We are not the best team, but we can fight to be the third best team in the championship and fight for podiums."
Williams finished the 2016 constructors' championship in fifth.
