Alex Wurz says he rates former team-mate Nico Rosberg the fastest driver over a single lap in the top flight, and has tipped the young German for great things in the future.

Rosberg joined Formula 1 from GP2 - where he clinched the crown in 2005, the category's inaugural season - and made an immediate impression, racing into the points on his grand prix debut and lining up an incredible third on the grid next time out in Malaysia. Last year - his sophomore campaign - the 22-year-out comprehensively out-qualified Wurz 16 times to one when the pair were both with Williams.

"Nico developed so much between the 2006 and 2007 seasons," the Austrian veteran told Motorsport Aktuell. "Especially in qualifying, I think he is the best in the paddock."

Wurz notched up 13 points last season - seven fewer than Rosberg - but unlike his team-mate rarely did he look a consistent threat to trouble the front-runners, which precipitated his decision to pull the curtain down on his racing career in the uppermost echelon a race early in China. He has since joined Honda as the Japanese concern's test-driver, a role in which he says he feels far more at home [see separate story - click here].

"We did our best to help him," underlined Williams engineering director Patrick Head, "but it didn't work."

Head acknowledged the highlights of Wurz's season - including third place amidst the chaos in Canada - but he added that on too many other occasions there was seldom "a sign that he could frequently go into the points".