Nico Rosberg, Mercedes, Jerez testing 2011Nico Rosberg insists that Mercedes will not show the full potential of its W02 until a major upgrade arrives for Bahrain, and says he is not paying any attention to the car's current disappointing pace.

Mercedes has not been a frontrunner in any of the tests so far, and Rosberg was only ninth quickest at Jerez today, 3.2sec off the pace. When asked about the car's apparent lack of speed, Rosberg replied: "Yeah, but we expected that. This is an interim car – it doesn't have a lot to do with the car we will have in Bahrain.

"We just need to put miles on it. It's important to get the systems working, like KERS, the cooling, and to work on reliability."

He admitted that mechanical issues today had made things more complicated for Mercedes, however.

"I could do many laps – that was positive," said Rosberg. "Unfortunately, there were a few small problems that put us back. The rear wing wasn't working properly, a small gearbox issue stopped me at the end and a sensor issue stopped me before that. So it wasn't a perfect day, but we are learning, and also for me as a driver it is important to do many laps."

Asked if the problems that had affected Mercedes' pace at Valencia were reappearing at Jerez, Rosberg said: "In a way, yes. But, at the same time, they were happy to see it, because it confirmed something we had in Valencia that was not easy to confirm at the time.

"Now, with the problem I had today, it made us understand fully. They made me do some things with the car, like pull the clutch, and apparently that allowed them to understand one of the issues."

The German was adamant that Mercedes should not be judged on its current form.

"We have a significant step for Bahrain, so that's why I'm not looking at the times," Rosberg said. "The others might have a step as well, but it's impossible to say yet. My rear wing wasn't working today, and that takes away so much from the lap time. It's really early days."