Nico Rosberg has warned that four-time world champion Sebastian Vettel can challenge Mercedes at the Malaysian Grand Prix.
Vettel narrowly missed out on pole position in a wet qualifying session in Sepang, but Rosberg believes that the Red Bull driver can convert his grid placing into victory.
He told reporters: "In the wet for sure Sebastian has a shot at the win, definitely. They're on it. In the dry even there he was looking quick this weekend so they are close in all conditions.
"[Red Bull] don't need to do warning signals, we're expecting them already. They are still the absolute benchmark in this sport and they are pushing like crazy so we expect them to close the gap."
Rosberg, who won the Australian Grand Prix a fortnight ago, will start third on the grid for Sunday's race.
