Lewis Hamilton has claimed Mercedes will look to "find our bearings" after a bad Friday left the three-time world champions as the third best team at Sepang.

It was thought the two Silver Arrows were simply easing their way into the Malaysian Grand Prix weekend when they were only sixth and seventh in the wet Practice 1 in the morning but when the Briton and his teammate Valtteri Bottas repeated those positions in Practice 2, the alarm bells began to ring.

What was particularly concerning was how nothing really seemed to work on the Mercedes' as both drivers went off the track on the Soft tyre early in the afternoon and then neither could hook up a competitive lap time on the Supersoft compound later on.

The result was a 1.4-second deficit to pacesetter Sebastian Vettel and Motorsport boss Toto Wolff suggesting there was a "gremlin" in the car which needed to be sorted out.

“It's been a very difficult day," said Hamilton, echoing his boss. "I've been struggling with the car today, so we have to review and try to understand where we have gone wrong with the balance. We're hoping that we're able to find our bearings overnight and regroup for tomorrow."

Historically Sepang has never been a great circuit for Mercedes with just a single victory coming in 2014, but Wolff admitted he was surprised by how the performance of the car on Friday was so different to how it was on similar layouts earlier in the year.

"You can compare Malaysia a little bit to Silverstone, probably, where we've been very good," the Austrian commented. "We've been very good in the high-speed, [but] we are not at all good in the high speed here.

"There's a fundamental issue in the car that we need to find out. They are very complex, so it can be a tiny detail."

What was equally concerning was the admission from Valtteri Bottas that his car wasn't actually feeling too bad on the circuit in terms of overall balance and setup.

"It's just a question of overall grip," he added. "We're definitely lacking some performance, it seems like Ferrari and Red Bull are very strong, so we have some work to do if we want to be on the front row tomorrow.

"The key area we are going to need to focus on tonight will be getting the maximum out of the tyres over one lap."