Fernando Alonso did not switch to BMW-Sauber because he would not have "fit" with the German squad's approach to formula one.

That is the suggestion of BMW's Robert Kubica, a close friend of the Spanish driver.

Pole Kubica, 23, has elected to stay with the Hinwil based squad next year, and earlier this season enthused at the rumours linking Alonso with a 2009 seat, declaring that the pair would "have a lot of fun" as teammates.

But he now tells Bild newspaper: "I think Fernando was never convinced about coming to BMW. As far as I know him, he would not have fit.

"There are differences of philosophies," Kubica added.

Like Alonso, Kubica makes no secret of his desire to see Ferrari's Felipe Massa beat McLaren's Lewis Hamilton to the 2008 crown.

Asked who he thinks will ultimately lift the trophy, he answers: "My head says Hamilton, but my heart says Felipe."

Kubica, whose rivalry with Hamilton dates back to their karting days, is critical of the British championship leader's on-track style.

"There are two approaches," he said. "Either you drive hard but fair, or you are overconfident and too aggressive."

Kubica said Hamilton's racing against Timo Glock and Alonso at Monza was "too much and dangerous".

He says he is not the only one who has complained about Hamilton's driving in driver meetings.

"It has been a topic and most see it the same way," Kubica reveals.