Injured Williams-BMW driver Ralf Schumacher will not return to the cockpit at next weekend's Hungarian Grand Prix, the team confirmed on Thursday.

The German has been sidelined after suffering fractured vertebrae in a crash at the United States Grand Prix, missing the races in France, Britain and Germany.

The 29-year-old had hoped to return for Hungary.

"We can confirm that, while Ralf's convalescence is progressing well, prudence dictates he will not race in Hungary," a team statement said.

"His condition will continue to be monitored on a race-by-race basis."

In Thursday's Bild newspaper the six-times Grand Prix winner's manager Willi Weber said Schumacher risked career-ending injuries if he returned too soon.

"Ralf's bone thickness was measured and it was established that the two broken vertebrae were not yet as hardened as is normally the case," he said.

"Another accident like the one in Indianapolis and Ralf could be made a paraplegic. Nobody could accept that."

Williams will announce on Friday who will replace Schumacher in Hungary.

Third driver Marc Gene of Spain replaced him in France and Britain while test driver Antonio Pizzonia of Brazil was given the chance in Germany.

Schumacher, who will move from Williams to Toyota next season, is now targeting the Belgian Grand Prix for his return.