Force India is already missing the input of its departed technical director James Key.

The team is locked in a close battle with Williams for sixth and seventh places in the constructors’ championships, which some analysts believe is worth $5 million.

Force India has had some difficult races recently, including in Singapore, where Adrian Sutil and Vitantonio Liuzzi qualified on the 8th and 9th rows of the grid.

The Silverstone based team and Williams then had a bitter post-race argument in the stewards’ office, with Sutil initially penalised for cutting a corner and then Force India lodging a protest about Nico Hulkenberg doing the same.

Sutil confided to Auto Motor und Sport that the loss of Briton Key to Sauber has not been without consequence.

“I actually thought there would be no problem,” said the German, who is thought to be close to deciding whether or not to stay at Force India beyond 2010.

“I have confidence in the people who have taken over,” Sutil continued.  “His successor Mark Smith is doing a good job, but I’m sorry to say that we have lost ground.

“It’s no longer easy for us to get into the top ten in qualifying.

“You only see how good a person really is when he is no longer there,” said the 27-year-old driver.