Ferrari dominated second practice for the French Grand Prix ahead of world championship leader Max Verstappen, with Carlos Sainz finishing ahead of teammate Charles Leclerc at the top of the timesheet.
The Spaniard, who scored his maiden victory at the British Grand Prix earlier this month, clocked a best lap in one minute and 32.527 seconds to beat his Monegasque teammate by 0.101 seconds.
But Sainz faces a grid penalty of at least 10 places after taking a number of new power-train parts on his car.
World champion Verstappen was a competitive third ahead of George Russell and Lewis Hamilton in the two freshly-updated Mercedes and Lando Norris who was sixth for McLaren.
“We have some work to do,” said Verstappen. “It is very hard on the tyres here and we needed a few more laps today.
“It is difficult to judge, but the tyres were hot.”
Hamilton, preparing for his landmark 300th Formula One race, was not impressed with the impact of the Silver Arrows’ efforts.
“Today, we’re in fourth and fifth so that’s kind of the region that we’ll be fighting for,” he said.
AS IT HAPPENED: Johns laments ‘hopeless’ Knights
READ MORE: Ponga left shattered after latest head knock
READ MORE: Star smashes 26-year-old record with ‘unbelievable’ run
“I don’t mean that we can’t be on the podium, I think we can still be up there.
“But we’re still not as quick as those front guys – and we’re a little bit further back than we were in the last race.” Mercedes had hoped to fight at the front on the smooth circuit that suits their car, but instead, said Hamilton, they “have a lot of work to do – a lot of ground to cover.”
“The car’s not spectacular here, we don’t know why, but hopefully overnight we can make a bit of a step,” he said, adding that the car lacked pace “everywhere”.
Kevin Magnussen was seventh for Haas ahead of Pierre Gasly of AlphaTauri, Daniel Ricciardo in the second McLaren and Sergio Perez, in the second Red Bull.
For a daily dose of the best of the breaking news and exclusive content from Wide World of Sports, subscribe to our newsletter by clicking here!