Aug.13 (GMM) BMW-Sauber should step up its efforts to replace Nick Heidfeld with former double world champion Fernando Alonso in 2009.

That is the opinion of Hans-Joachim Stuck, a famous German driver who contested grands prix in the 70s and now heads up Volkswagen's racing division.

Stuck, who prior to his VW appointment was long associated with BMW, believes the German marque should strive for a long-term contract with Alonso to partner Robert Kubica.

"It's nothing against Nick, but unlike Kubica he is not a driver who can win a world championship," Stuck plainly told Sport Bild.

Heidfeld, the 31-year-old veteran with nearly 150 grands prix to his name, has struggled alongside Kubica with the F1.08 car this year.

Stuck said Alonso is the ideal alternative.

"If you can secure an Alonso for the long term, then you must," he insisted.