Despite Lewis Hamilton having extended his advantage at the head of the drivers' championship to 34 points with second place in Malaysia, alarm bells have rung at Mercedes about its form against rivals Ferrari and Red Bull.

Mercedes had a particularly difficult time in Malaysia, with neither of its drivers able to find a good balance with the W08, as Red Bull took its second win of the season and Ferrari's Sebastian Vettel charged from the back of the grid to fourth.

Wolff said that although the team could take some satisfaction from extending its points situation thanks to Ferrari's engine woes, it was mindful of the pace shown by its Italian rival.

"This is a sport where you take no prisoners," said Wolff. "We take the points and Ferrari would have done the same, but somebody else's misfortune or underperformance doesn't cheer me up at all.

"We are looking at our own performance, our own level of performance, whether it was good enough or better than anybody else's, and that is the underlying feeling that exists at the moment. How can we fix our issues?

"Benefiting from Ferrari's problems in the championship shouldn't hide that they have caught up 30 seconds this race."

Wolff said that the team had explored its situation in detail immediately after the Sepang race, and the sense he had from his engineers during a lengthy debrief was that the 'pain' of its situation was pushing his men to respond.

"It is these moments that make you progress and I had the best race debrief in five years right now," he said. "This is the feeling I have because it is just so painful.

"We benefited in the championship from the misfortune of Ferrari, but we didn't have the pace to challenge either Red Bull or Ferrari, and this is what remains the underlying feeling with all of us. We need to understand why we underperform on certain circuits and certain ambient conditions."

Wolff is convinced that the pattern of form seen in the last two races does not point to Mercedes having fallen back in the development rate. Instead, he thinks some factor has contributed to it under performing.

"Full credit to Red Bull and Ferrari for their performance - but I think we have underperformed in Singapore and we have underperformed in Kuala Lumpur," he said. "This is what we need to concentrate on."

Asked if he was worried about the lack of pace against Ferrari, he said: "I am always worried, and the pace from Ferrari and Red Bull was very good. But a bit of a shake is good from time to time."