Sidecar racers have the biggest cojones
Heidfeld admitted, however, that it was an opportunity that he could not miss, even if he is unsure if he will see out the season.
"Whether it is for the whole season is not clear right now, but of course I am ready and available for the whole season! The biggest sensation is that I did not expect to race this year," he said.
Interestering comments fro Heidfield.Do Lotus Renault expect Kubica to return this year.
Robert Kubica has undergone a fourth operation in hospital in Italy today.
Doctors treating the injured Pole had initially hoped that he would only require the three operations carried out in the days following his rally crash last month.
But today further surgery was carried out to help the mobility of his injured elbow. Italian media reported that the operation was conducted by Dr Luigi Celli and Dr Francesco Lanza, and that his rehabilitation will resume in the coming days.