Ralf Schumacher will step back into a Formula One car on Tuesday for the first time since he crashed heavily at the United States Grand Prix in June.

The German, younger brother of Ferrari's seven times world champion Michael, has missed the last six races while he recuperates but Williams hope he will come back strongly in testing at Silverstone.

The BMW-powered team are eight points clear of McLaren in the battle for fourth place in the championship with three races remaining.

"Ralf will test on Tuesday," confirmed team technical director Sam Michael at the Italian Grand Prix.

"Hopefully he'll do three days at Silverstone, everything will be okay and then he'll race in Shanghai. Because he's a guy with a lot of experience in the car we have missed him, it's been detrimental.

"The gap is only eight points and you can lose that in one Grand Prix so it's just not enough of a bumper to be comfortable at all."

Ralf, who is moving to Toyota at the end of the year, had hoped to return at Monza -- the fastest track on the calendar and a race he also missed last year after a heavy crash -- after being passed fit by doctors.

But insurers had stipulated a minimum 12 weeks' recovery time and neither Ralf nor the team were willing for him to race uninsured.

"Ralf was passed medically fit and mentally fit -- I don't think they even talked about that -- he had some cognitive tests as well which he sailed through, of course," said team boss Frank Williams.

The driver, who suffered spinal fractures in the high-speed crash at Indianapolis on June 20, has been training hard for his comeback. Spanish test driver Marc Gene and Brazilian Antonio Pizzonia have stood in for him in the meantime.