Mercedes is wary of another drop in form at this weekend's Russian Grand Prix if it fails to get the super-soft and soft tyres working at the Sochi Autodrom.

Mercedes has been the dominant force at nearly every circuit this year, but in Singapore last month a weakness was exposed as Lewis Hamilton and Nico Rosberg struggled to get their tyres working. The same two compounds used in Singapore will be on offer again at Sochi and team chairman Niki Lauda is concerned that the smooth track surface could see the same problem return.

"Everything went well at the last round in Japan, so thank goodness we came out of the Singapore trauma and we are back," Lauda said. "But my worry is Sochi, which has Singapore type of asphalt, is not that easy. We have to work hard and stay competitive, then we are looking good."

Team boss Toto Wolff says Mercedes cannot to take its Suzuka level of performance -- where the Hamilton and Rosberg scored a one-two -- for granted.

"Japan was an important weekend for the team. We had to hit back strongly after Singapore and that objective was achieved on all fronts - in the cockpit and in the garage. While we take satisfaction from these successes, however, we do not lose sight of our failures. There are still many obstacles left to overcome this season and we must continue to tackle them with full force.

"We return to Russia with positive memories from last season, when the team sealed the first Constructors' title for Mercedes-Benz with a 1-2 finish. A repeat performance in Sochi would be fantastic and this is absolutely the target - but we are under no illusions that it will come easy. The job is not done yet."