As the formula one world this week dashes across Europe between the Spa-Francorchamps/Monza double header, rumours abound about possible driver changes for the future.

Despite Sebastien Bourdais enjoying a strong weekend in the Ardennes, the Belgian paddock on Sunday night buzzed with speculation the Frenchman's days at Toro Rosso may be extremely numbered.

Indeed, some sages whispered that Sunday's Italian grand prix could be his last, as the Ferrari-powered squad possibly turns to giving 2009 contenders Takuma Sato, Sebastien Buemi and Bruno Senna the opportunity to prove their worth at the remaining races of this season.

There is also movement behind the scenes at Renault, where the future of the Brazilian rookie Nelson Piquet looks in doubt.

Indeed, it is reported by Switzerland's Motorsport Aktuell on Monday that another Brazilian - 24-year-old test driver Lucas di Grassi - is to test for the French team on all three days of the forthcoming Jerez test.

The report said the test is an evaluation with possibly replacing his countryman for 2009 in mind, amid uncertainty that di Grassi's recent strong form in GP2 can cross over to the senior series.

It was also rumoured at Spa-Francorchamps that grand prix veteran Nick Heidfeld, whose Seat at BMW-Sauber seems insecure for 2009, may be a contender to race with Renault next year.

Source: GMM