Niki Lauda fears Singapore GP repeat for Mercedes in Russian GP

This weekend F1 returns to Sochi, the scene of Mercedes' maiden constructors' championship triumph a year ago after Lewis Hamilton led home a one-two.

With Mercedes currently 169 points clear of Ferrari, the German manufacturer simply has to score three points more than its Italian rival on Sunday to clinch back-to-back crowns.

Although Mercedes bounced back from its troubled Singapore GP with a dominant performance in Japan, non-executive chairman Lauda recognises Sochi could represent more challenges in terms of tyres.

"Thank God we came out of the Singapore trauma and we are back, that's all I can say," said Lauda.

"It's a big relief we are back where we should be, this is very simple. We are doing what we should do.

"But the championship is not over because my worry is this next race at Sochi has Singapore-type asphalt.

"So it's not done and not that easy. We have to work hard, stay competitive and then we are looking good, but you only look good when it is done."

For Russia's debut race at Sochi last year Pirelli opted for a conservative choice with its rubber by selecting the soft and medium compounds.

It resulted in a one-stop race, even for Nico Rosberg who pitted at the end of lap one after severely flatspotting his opening set of tyres before running for 52 laps on the mediums.

Pirelli has chosen its softest two compounds for this year with the aim of making it a two- or three-stop race.

Mercedes executive technical director Paddy Lowe said: "This was a tricky weekend last season, with a new circuit to learn and fresh Tarmac which produced slightly unusual behaviour from the tyres.

"This year we have moved one step softer on the compounds to bring the soft and supersoft into play - perhaps influenced by Nico running almost the entire race last year on a single set of tyres.

"One year on, the track surface will have weathered differently so we must ensure we have all eventualities covered."