Nico Rosberg says Mercedes needs to turn around a one-second deficit compared to 2015 to win the Singapore Grand Prix.
While it was dominant at the majority of circuits, Mercedes was surprisingly uncompetitive in Singapore last year as Sebastian Vettel took pole position and won ahead of Daniel Ricciardo.
Asked if he is confident Mercedes will not have a repeat performance this year, Rosberg replied: "Not at all, because there were reasons we were off the pace.
"We understand some of them, we made some major changes so we hope to be looking a lot better but is it enough to turn around a one-second deficit we had last year? It’s not an easy one.
"It is a cool track which I feel comfortable on but this weekend is going to be a special challenge for us because we have to get everything 100 per cent right to be able to challenge Ferrari and Red Bull. Steep weekend in front of us."
With team-mate Lewis Hamilton admitting he is concerned a number of poor starts could end up costing him the title, Rosberg says it is an area of focus for him to ensure he retains the upper hand.
"Of course I am aware of the fact that starts are an ongoing challenge and it will not become easier now for us. So definitely it needs attention on my part, but I have been feeling good lately, been having some good starts, so feeling good about it.
"But I have also had my difficulties – I lost the Hockenheim Grand Prix and the Hungarian Grand Prix for not optimal starts. So it is a good challenge."
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