Mark Webber is 11 points clear at the top of the drivers' championship, while his teammate Sebastian Vettel - 21 points further adrift - is also still in the running.

"With Sebastian we will take an aggressive strategy, while with Mark we can be safer and let him drive more defensively," Dr Marko is quoted by Germany's Auto Bild.

German Vettel, 23, confirmed that he is not prepared to write off his chances of beating Webber and his other rivals to the title.

"It will be tight but I'm optimistic," he told the German language TV Movie.

"There are still four races to go; to throw in the towel now would be stupid," added Vettel.

He said recently that Suzuka, the scene of next weekend's race in Japan, was "made for" Adrian Newey's RB6 car.

"We still have to go there and prove it," said the 2009 winner and pole sitter.