Niki Lauda admits he is worried Mercedes could face a repeat of its problems in Singapore at this weekend's Russian Grand Prix.
Mercedes struggled to get the soft and supersoft tyre compounds to perform in Singapore, while Ferrari and Red Bull both extracted the maximum from the tyres to comfortably beat the defending constructors' champions. While Mercedes wrapped up the aforementioned title in Sochi last year, the tyre compounds have been changed after a dull race in 2014.
With this season seeing the soft and supersofts again nominated in Russia, Lauda says it could lead to another challenging weekend.
"My worry is Sochi which has Singapore type of asphalt, so it is not that easy," Lauda said. "But we have to work hard and stay competitive, then we are looking good."
Mercedes executive director (technical) Paddy Lowe agrees the team needs to work hard to ensure it gets its tyres working properly in Sochi.
"This was a tricky weekend last season, with a new circuit to learn and fresh tarmac which produced slightly unusual behaviour from the tyres," Lowe said. "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."
Red Bull: Burning bridges everywhere
F1i technical expert Nicolas Carpentiers takes us through exclusive pictures of Renault's power unit
Click here for the F1 drivers' girlfriends gallery
Keep up to date with all the F1 news via Facebook and Twitter
