After many consecutive years at the grand prix circuits, the 39-year-old Spaniard will watch this weekend's Singapore action on television from his Zurich home.

He has been ousted at Sauber by Nick Heidfeld, who was previously incoming official supplier Pirelli's permanent tire tester.

It had been expected that de la Rosa, with years of experience as a test driver at McLaren under his belt, would immediately replace Heidfeld.

But this week's Monza running in the Pirelli-shod 2009 Toyota was conducted by Romain Grosjean.

Spanish news agency Europa Press said the Swiss-born Frenchman is staying on board, to share the role from now on with de la Rosa.

"So far, our work has been done by Nick Heidfeld, but since he has returned to racing, he will be replaced by Pedro de la Rosa and Romain Grosjean," confirmed Pirelli chief executive Francesco Gori at the Turkish factory where the F1 tires will be made.

"They (de la Rosa and Grosjean) will test until the Abu Dhabi grand prix, and after that the teams will use the new tires," he is quoted in the EP report.