Heidfeld aware of pressure to perform

Heidfeld has finished in tenth and ninth in the last two grands prix, while teammate Robert Kubica has scored points in both, including a third place finish in Valencia nearly two weeks ago.

BMW Sauber have told Heidfeld that he must raise his game to convince them to renew his contract for next season, and the German driver admitted on Thursday he is aware of his situation.

"I put myself under pressure more than anybody else from the outside," Heidfeld told a news conference ahead of the Belgium Grand Prix.

"It is pretty clear that if one car finishes on the podium and I finish ninth then nobody needs to tell me anything."

Heidfeld also confessed he was surprised to see his problems return after he thought he had made a breakthrough in performance during the middle part of the season.

"Testing goes well but does not mean it will be perfect here," he said. "I was happy with Monza testing, I tried a couple of things which will likely only work at Monza so it is not looking too bad. I also tried some things which should help me."

"Obviously it is all about understanding the problem and changing something. I was in a similar situation a while ago this year and I thought I had them a bit behind. Then I was surprised to have similar problems in Valencia. I knew where to search and thought we had solved problems but not."

Heidfeld received the backing of teammate Robert Kubica, who defended the German's performances.

"I'm not the team boss, so I don't have this problem," he said when asked if he would retain Heidfeld. "It's very, very difficult. People like to forget what Nick has done in the past.

"If you look at how a situation can change from one year to the other, you have to look at the bigger picture, not just at what you want to see.

"Nick is a very good driver, and he has shown that many times. I struggle to find someone who is quicker."

Kubica said, however, that he would not have a problem if his teammate changed next year.

"I've never had a problem with my teammate, so for me there is no difference," he added. "There are always teammates where you can learn something, and if someone new comes along then I could pick up something different he is doing.

"At every point you would pick up positive points in some way. You need to do that because you are never perfect.

"We have been team mates for two seasons, two and a half by the end of the year, and all in all we have very good moments and worked very well together.

"So I don't see why we can't be teammates again next season, but as I said, I would have no problem with a different driver as well."