WilliamsF1 driver Nick Heidfeld has revealed that he is operating at only 50 percent of his normal fitness level.

The German, who has signed to drive for BMW next season - presumably with his good hand - will miss the Japanese and Chinese Grands Prix - having already missed the previous three races following a succession of incidents.

A crash during testing at Monza left him with a headache which ruled him out of the Italian and Belgian Grands Prix, whilst a bicycle accident, over the course of the Spa weekend, left him with a cracked shoulder blade.

Talking ahead of this weekend's race at Suzuka, where he will once again be replaced by Antonio Pizzonia, Heidfeld said: "I have not yet overcome the injury, but the worst is in the past.

"During the first five days after the accident I couldn't even move my arm," he revealed.

"In my current condition, it is simply not possible to race. At home, I have a simulator to train my steering strength and my muscles. At the moment I can only achieve 50 percent of my original physical capabilities. It's not possible to move fast as the shoulder inflammation is too strong. The doctors tell me that it takes four to six weeks to fully recover from such an injury."