Ralf Schumacher will make his return from injury in a three-day test at Monza next week, his stand-in at Williams Antonio Pizzonia says.

The German has not driven since fracturing his back in a high-speed crash at the United States Grand Prix at Indianapolis on June 20.

"He is going to be testing after the race here (in Belgium) in Monza for three days," said Brazilian test driver Pizzonia, who will once again deputise in Sunday's Belgian Grand Prix.

Spaniard Marc Gene was promoted to the race team for the French and British Grands Prix but failed to score any points.

Pizzonia has since competed in Germany and Hungary and picked up four points for two seventh positions.

Pizzonia said on Thursday a decision on whether Schumacher, the younger brother of six-times world champion Michael, returns for the Italian Grand Prix at Monza in two weeks will be made after the test next week.

"We will see how he is going to be after the test," he added. "If he is ready he will be racing at Monza as far as I know."

Schumacher scored just 12 points in the opening eight Grands Prix before his crash in the ninth round of the 18-race season.

The German will leave Williams, whom he joined in 1999 from Jordan, at the end of the season to join Toyota.