McLaren pair await Red Bull trump card

Lewis Hamilton and Jenson Button both fear Red Bull Racing have something up their sleeve that will see them again clinch pole for tomorrow's Turkish Grand Prix.

Hamilton finished quickest at the end of Friday's first practice and McLaren team-mate Button topped the timesheet with the best lap of the day come the conclusion of the second 90-minute session. The duo sandwiched the Red Bull pairing of Mark Webber and Sebastian Vettel in the afternoon, but there is genuine concern their rivals were sandbagging.

"I have no doubts that in qualifying the Red Bulls will pull out something extra, which they always seem able to do," said Hamilton. "I think they'll be very quick, along with the Ferraris, although I do feel we will be able to compete with them."

He added: "We're always fast in practice, but they always go a little faster in qualifying, and I expect that."

Button, whose time of one minute 28.280 seconds was marginally quicker than last year's pole lap from Vettel, echoed Hamilton's comments.

"My car is good, but I don't think the Red Bulls are showing their hand yet, so don't get too excited about our pace," said Button.

"The Red Bull is still the car to beat, and we will see where we stand.

"We're positive people and so let's hope we can challenge them, but it's going to be difficult."