Lewis Hamilton says that the difference between the W14's handling since last weekend is like "night and day".

Though seventh on the timesheets, and just 0.338s off the pace, Hamilton was clearly struggling, as was teammate George Russell who finished the day 10th, 0.541s off the pace.

Only last weekend, courtesy of its last significant upgrade of the year, including a new floor, the W14 was an entirely different beast according to the seven-time world champion, who was subsequently disqualified.

"Not that great," he replied, when asked about the opening day's running. "Dodgy... not dodgy, but not the greatest... a bit of a struggle.

"I mean the car is night and day different compared to last week," he continued. "I don't know what to say, you just never know what you're going to get with this one.

"Some days she's great and some days she's not," he admitted. "It's hard to extract the lap, though I think there is definitely performance there. It's just hard to extract it and it's quite peaky this weekend with the aero map or whatever it might be.

"So, we are going to work on it overnight but definitely it wasn't a fun day compared to FP1 in Austin. We are a bit off but hopefully overnight we can find something and tomorrow the car will be better to drive."

Asked what the team hopes to discover overnight, he admitted: "I'm not sure. Again, we never know what to expect with this car, maybe we make the changes, and we'll pick that pace up.

"I think there was definitely some performance in there to be closer, maybe in the top three. But we've got to figure out how to make it easier for us to extract that performance, so that's what we'll be working on tonight."

"It was a bit of a tricky session," added teammate Russell. "There's rain around here and there, plus we have the prototype Pirelli tyre and it is a very tight field out there.

"I think there is potential," he added. "I think we've got a lot of work to do overnight.

"It's very tight, especially with some unexpected cars, to be honest, some cars in the Top 10 that we weren't expecting to be there. But we feel like we've got a lot to improve, but we've got the opportunity to do it as well."

Asked what improvements can be made overnight, he smiled: "Faster race car to be honest.

"We've been probably in the wrong window today," he continued, "I think. Lewis and I were running two different setups and we probably both weren't in the right window.

"So, that's given us an indication that probably halfway between both is the right place to be. So, that is frustrating in the moment to have a negative car and not have the best of days.

"But through those difficult moments you learn probably more than when the car is in a better place. That's what practice is all about."

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