Kimi Raikkonen could achieve more at Ferrari if he worked harder on the technical side of his job, suggests the man who gave him his Formula One break.
Raikkonen has not taken control of Ferrari as expected
The Finn is "unbelievably fast, focused and powerful," Peter Sauber said.
"But it would be interesting to see how good he could be if he concerned himself with the technology side, too."
Raikkonen is tied for the championship lead after three races but was beaten in Bahrain recently by team-mate Felipe Massa, who he was expected to outclass.
Former team owner Sauber, who sold his majority shareholding to BMW, emphasised that he "would not call his lack of technical interest a weakness" and that Raikkonen had "a huge amount of natural talent".
But, talking to German magazine Auto Bild, Sauber did admit Raikkonen's "strengths are definitely not on the technical side".
Raikkonen, 27, is regarded by many as the outright fastest driver in F1, but he makes no secret of the fact that he is not interested in anything other than driving fast.
I believe Kimi could follow in the footsteps of [1980s legend] Gilles Villeneuve, rather than Michael
There was much speculation before this season about how the former McLaren driver would adapt to life at Ferrari as a replacement for Michael Schumacher, who was much more involved in the workings of his team.
However, Williams driver Alexander Wurz, who was test driver at McLaren when Raikkonen was at the team, believes he will achieve great success as long as Ferrari do not expect him to be something he is not.
"Kimi will do just fine at Ferrari - better than fine," Wurz told F1 Racing magazine.
"Once they've accepted that he's Kimi and not Schumi, they'll learn to love him - because he's easy to understand and therefore to love, a big talent who just enjoys what he's doing.
"And if he's good at it, which he is, and he's consistent over a number of seasons, then I believe he could follow in the footsteps of [1980s legend] Gilles Villeneuve, rather than Michael.
"And if things work out like that, then they might well be just perfect for both Ferrari and Kimi."