Nico Rosberg says Mercedes need to be "cautious" ahead of what he expects to be a tricky Russian Grand Prix for the world champions.
Mercedes scored a comfortable one-two in Japan as it bounced back from the bizarre drop in performance in Singapore, which it linked to Pirelli's decision to take the soft and super-soft tyres to Marina Bay. The tyre manufacturer is bringing those same compounds to the Sochi Autodrom this weekend and Rosberg admits that, and the unique asphalt at the circuit, complicates matters for Mercedes.
"It's very particular because the asphalt is quite particular here, it's quite different," Rosberg explained. "Therefore there are some new challenges you need to handle. The tyres being softer is going to be more different to last year, because last year I did the whole race without any pit stop other than the first lap. It's going to be quite different and we need to adapt to the situation. Could be an interesting one."
However, Rosberg thinks Mercedes has learned the reasons it struggled on the softest Pirelli compounds in Singapore.
"It's very unique, this race, with the asphalt and the super-soft/soft compared to last year's soft/medium, so it will be a particular challenge. We did show weaknesses on the soft/super-soft last year -- big weaknesses -- which we have learned from. But here is not Singapore so we need to really do a good job and it's not going to be as simple as Suzuka was in terms of preparation."
Mercedes needs to outscore Ferrari by just three points this weekend to wrap up the constructors' championship, which it also did at the Sochi circuit last season.
"It was one of the aims of this weekend, to try and clinch that. It's special to be able to do it again in such a dominating manner -- really awesome job from the team -- and close it down so early. But Ferrari has been strong recently, very, very strong even, so we need to be cautious and still work hard to get the best out of it, but of course we're optimistic."