Rubens Barrichello faces the prospect of a 5-place grid penalty as his team waits before deciding on whether to change the gearbox in his car.

Speaking in the wake of today's qualifying session, in which the Brazilian finished fifth, team boss Ross Brawn admitted that the team was considering changing the unit, which is believed to have suffered damage in the closing stages of the Belgian Grand Prix, its first race of a mandatory four.

"We're going to have another look at all the information," Brawn told reporters. "However, there's no decision yet.

"The fuel weights have been published so we can now do all the calculations and see how the race would run and then decide," he added. "I think in the morning we will make a decision.

"There is a reliability risk," the Englishman continued. "It's a question of balancing that against a very good qualifying position with the fuel he has got on board."

Barrichello, who qualified ahead of his teammate, while carrying 1.5kg more fuel, said: "There is a little bit of a conversation with the team. I don't want to be leading the race and have a failure. At the same time, I have to fight for what I really can achieve which is winning tomorrow.

"It's almost like if I win tomorrow you have a penalty some other time," he added. "But it will be very silly to be winning and also have a penalty. "At the moment I would prefer to keep it"