Jul.9 (GMM) Nick Heidfeld got his formula one season back on track at Silverstone, BMW-Sauber boss Mario Theissen predicts.

Heidfeld, the 31-year-old German, has struggled to keep up with his teammate Robert Kubica this season, sparking speculation about his future with the Swiss based outfit.

He finished second to Lewis Hamilton with an error-free run in the rain-affected British grand prix, while Poland's Kubica struck technical trouble in qualifying and then spun out of the race.

But Theissen said there were other signs at Silverstone that showed Heidfeld has turned a corner.

"In practice he was always on the same level as Kubica. He showed that he is comfortable again in the car and on the limit," the German told Auto Motor und Sport.

He told the German newspaper Bild: "I expect him to be with the same form at the next race as well."

Heidfeld was also happy with his performance in Britain. "There is still more potential to be extracted, but at least I am now on a reasonable level," he said.

Theissen was also happy that BMW-Sauber seems to have returned to form following a lacklustre showing at Magny-Cours two weeks earlier.

"At Silverstone we were back to normal," he said. "14 days ago I doubted that we could keep up with our rivals' development speed. But at Silverstone I no longer had the impression that we are falling behind."