Ferrari Formula 1 drivers Sebastian Vettel and Charles Leclerc are doubtful Friday’s practice results will be a true reflection of the pecking order at this weekend’s Belgian Grand Prix.

Vettel topped opening practice ahead of Leclerc as the Ferrari pair finished over a second clear of Mercedes drivers Valtteri Bottas and Lewis Hamilton, before the roles were reversed in the afternoon as the Scuderia maintained its advantage.

Following Friday’s running, Hamilton suggested Mercedes was losing “nearly a second” to Ferrari on Spa’s straights alone, but Vettel is not convinced that Mercedes has shown its hand.

“It’s Friday, I think we have seen this on a couple of Friday’s already,” Vettel said. “The most important thing is that we pick the right Ferrari shoes for Sunday.”

Asked if Mercedes can challenge for pole in qualifying, the German replied: “Of course they can.

“As I said, it’s not the first time that Ferrari looked good for us. Probably Saturday morning will look good for us and then we will see what happens on Saturday afternoon. I’m not taking anything for granted.”

Leclerc ended up over six-tenths clear of Vettel in FP2 but is expecting the gap to close significantly on Saturday, while he is “pretty sure” Mercedes will fightback once it turns up its engine.

“After the holidays a day like this is good,” he added.

“Qualifying pace was very strong, race-pace a little bit less so we have to improve that for Sunday, but we look OK.

“In the second sector they [Mercedes] are very, very strong and tomorrow they will turn up the engine and they won’t be that bad in the first and final sectors.”