Ralf Schumacher has vowed to return to Formula One only when he is fully recovered from the injuries he suffered at Indianapolis.
The German crashed backwards into a concrete wall at high speed during the United States Grand Prix, cracking vertebrae in his spine. His injuries were expected to keep him out for up to three months, which would mean a probable return in Italy in September.
But with Schumacher having signed a deal to drive for Toyota next season there are suggestions he will not compete again this year while other sources suggest an August return in Hungary is possible.
The 29-year-old is keen to get back behind the wheel of a Formula One car but insists he will take no risks with his health.
He said: "My health is top of my list at the moment. I'm making progress every day but I don't want to start speculating as to when I'll be making a return to the cockpit. Naturally I would love to jump back behind the wheel of a Formula One car, it's what I love doing.
"But I'm determined to take my time and only get back into the cockpit when I'm properly fit."
Antonio Pizzonia will fill in for Schumacher in Germany next weekend after fellow Williams test driver Marc Gene was dropped after two disappointing races as a stand-in.