Felipe Massa happy to turn teacher for Williams team-mate Lance Stroll

Felipe Massa believes he had his hardest-working day in F1 on Tuesday when he completed the equivalent of two-and-a-half Spanish GPs to put Williams back on track in pre-season testing at Barcelona.

After two crashes for Lance Stroll during the first week of testing severely curtailed Williams' involvement, Massa, who has un-retired from F1 to return to the team after Valtteri Bottas' switch to Mercedes, set the fastest time of Day One for the second test.

TEST REPORT: Williams and Massa surprise at Barcelona

But it was the veteran's lap count which was arguably even more impressive than his headline lap time.

"I am so happy for the day, I don't remember before doing a day with 168 laps in my career!" the Brazilian said. "It was a lot of laps and l can feel it a bit on my body, but l am good. I feel in good shape in for the new season.

Already a valuable commodity, Massa's experience will be of extra value for the Williams team in 2017 as they bed in rookie Stroll - whose pace and novice status have been apparent in equal measure already this winter.

"Lance needs to learn, he needs to understand the car and get more mileage," Massa told Sky Sports News HQ. "I am trying to pass on everything l can - definitely for the team but also for him - and just trying to make sure he is learning as quick as he can.

"If he is ready and he is doing a good job then it is for the team and for myself as well as his team-mate."

Williams joined frontrunners Mercedes, Red Bull and Ferrari in becoming one of only four teams to lap below the 1:20 mark at the Circuit de Catalunya when Massa set his table-topping time just before lunch, but the 35-year-old says it is too early to conclude the Grove outfit are among the frontrunners.

"I don't think we are on the same level as Mercedes," said Massa. "Mercedes have already shown incredible speed. But if we can fight podiums then that will be a great job. We will see where we are in Australia."