Mercedes has moved to downplay suggestions a chassis switch between Lewis Hamilton and Valtteri Bottas contributed to their performances on Friday in Paul Ricard.

Ahead of this weekend’s Formula 1 French Grand Prix, the pair switched chassis, with Bottas using that driven by Hamilton at Monaco and Baku.

The Finn duly topped the opening 60-minute hit-out before lapping just 0.008s slower than Max Verstappen in Free Practice 2.

By contrast, Hamilton struggled despite timing suggesting he’s within touching distance of his team-mate.

Bottas revealed the chassis switch on Thursday, stating it was a planned change for this weekend.

“It’s not a new chassis, it’s different,” he said.

“It was always planned for me to change to a different chassis at this point.”

Hamilton has struggled in the two most recent grands prix, failing to score in Azerbaijan two weeks ago, an event preceded by a seventh-place finish on the streets of Monaco.

Bottas qualified third fastest for that event, before a stuck wheel forced him out while running second.

“We swap parts around all the time,” team boss Toto Wolff told Sky Sports when quizzed about why his drivers had switched cars.

“This is part of the planning as these are carryover chassis, they’re around for a second season, so we’re not accumulating millions of miles on one.”

Wolff moved to further ease concerns by suggesting that, should either Hamilton or Bottas feel that there is something fundamentally wrong with their new machine, that they could switch it out.

“If it calms the driver’s mind, we have a spare chassis, which is a brand new one, we can always do that,” he said.

“It’s the chassis that was splendid in Monaco,” he added of the car Hamilton is now driving, playing down any implications that it’s somehow deficient.

“I mean, you listen to the engineers and said it’s all tested and it’s stiff.

“There shouldn’t be any difference but if the driver feels that it’s not then it’s definitely not worth trying to make a point here, then you just need to change.”

Following Friday’s running, Bottas admitted he had more trust in the W12.

“The balance is good, the tyres are working well, I’m confident with the car, I can trust the car. I think that’s the biggest difference,” he said.

Hamilton was more reserved in his comments, suggesting his relative lack of pace was more the result of getting to grips with the tyre’s this weekend.

“It’s a different track, so very rarely do you ever have any differences between the chassis,” he began.

“They all feel pretty bad,” he added of the tyres.

“I think the hard is probably the better feeling one because it’s quite seems quite a heavy duty with the temperatures here – the softer you go, the worse it feels.

“I would imagine the hard is going to be the one that most people can’t wait to get on to, but I’m not really quite sure which tyre is quicker.

“The soft tyre seems to run out halfway through the lap and then the medium tyre, I think is a little bit more resilient, but doesn’t give you a huge amount of grip.”

An hour of practice remains for teams ahead of qualifying for Sunday’s French Grand Prix, Free Practice 3 scheduled for 20:00 AEST this evening.