Sunday at Monza was Pedro de la Rosa's last Grand Prix with the Sauber team in 2010, according to a Swiss report.
The Blick newspaper, with close links to the Hinwil based team's chief Peter Sauber, said Nick Heidfeld will definitely be driving the Ferrari-powered C29 from now on, starting with the Singapore night race in two weeks.
The news will almost certainly result in Nick Heidfeld, who this year was formerly Mercedes' reserve driver, relinquishing his new role as test driver for the 2011 tyre supplier Pirelli.
It will be the third Sauber tenure for German Heidfeld, 33, who also drove for the Swiss team in 2000-2003 and 2006-2009.
"This makes sense," wrote veteran Blick correspondent Roger Benoit, "because Sauber wants to make up the 20 point arrears to Williams, in order to finish the world championship in seventh position."
Compared with rookie teammate Kamui Kobayashi's 21 points, long-time McLaren test driver de la Rosa has scored just 6 points on his return to the F1 grid this season.