Nico Rosberg claims use of race drivers at 'secret' test was to benefit Pirelli

Nico Rosberg has insisted that it was to Pirelli's specific benefit that both he and Lewis Hamilton, rather than Mercedes reserve driver Sam Bird, drove the W04 in the secret Barcelona test.

Since the existence of the 'secret' three-day test broke on the morning of the Monaco GP, Mercedes have been at pains to insist not only did they receive permission from the FIA to participate but that the event was held at the prompting of Pirelli after a series of high-profile tyre failures. "We had nothing to do with the test," Rosberg maintained to Sky Sports News. "Pirelli were there and they said 'do this for this many laps and now this for this'. It was completely a Pirelli test for them to learn about their tyres. "I just tried to give them as much information as possible from what I was feeling to help them with their tyre development programme." The furore continues to overshadow Mercedes' positive start to the season, with Rosberg chasing a fourth-successive pole position as well as consecutive victories. With the long straights of the Gilles Villeneuve circuit providing ample overtaking opportunity, grid position is not expected to be as critical this weekend as it was around the notoriously tight-confines of Monaco where Rosberg led the pack from start to finish. "Qualifying has been very good and our car has been the fastest for quite some time now," the German acknowledged. "We have a very, very fast car and I'm confident I'll be quite far up the grid. "It's a different situation here because it's lower downforce and that could mix things up a bit. So let's wait and see but qualifying should be good. We need to be careful, because some of the other teams might be stronger, but in general we should be there or thereabouts." Were Rosberg to once again claim pole then it would also represent a fourth successive defeat of Hamilton, regarded by many observers as the fastest man on the grid, in identical machinery. Their increasingly-compelling in-house contest carries another intriguing dimension this weekend given that just as Rosberg has never been out-qualified by his team-mate in six previous visits to the Gilles Villeneuve circuit, neither has Hamilton. Something - or rather, someone - has to give this Saturday. "It's a track I like and I'm confident coming here," mused Rosberg. "Qualifying is going to be exciting and important - although maybe a little less important because you can overtake here and tyre degradation will be an issue. In any case, and as at all tracks, it will be a big challenge to be ahead of Lewis in qualifying because he is very, very quick."