Bahrain GP: McLaren F1 team further off pace than expected

Mercedes has dominated the 2014 season so far, with two poles and two commanding victories, including a one-two finish in Malaysia last weekend.

The team continued to set the pace at the Sakhir circuit, with Lewis Hamilton and Nico Rosberg finishing on top of the times in Friday practice.

Button, whose team has not won a race since 2012, is under no illusions about the time it will take to be able to match Mercedes.

"It's going to take a long time. I think the closest team to Mercedes is Red Bull," said Button after posting the sixth quickest time in the evening session.

"For us, it's a big gap, which is a shame. It's bigger than we expected and we have been putting improvements on the car.

"So a lot of work needed for us to catch the Mercedes, and it's definitely not going to happen overnight."

Button said his MP4-29 felt more consistent than at Sepang last weekend, when McLaren was not in contention for a podium finish, but he accepted that Mercedes is out of everybody's reach.

"I think no one except for Mercedes is happy with their car," he said.

"They are so much quicker than everyone else. We are working very hard to improve.

"It's not too bad. It's better than Malaysia in terms of consistency.

"We still have a lot of work to do to be competitive. One [Mercedes] came by me like I was standing still."

Team-mate Kevin Magnussen agreed with Button, but the Dane reckons the cooler temperatures in Bahrain's night running could help McLaren.

"I think we have some opportunities here with the colder temperatures," he said.

"Maybe we can do something, but it's not going to change the world. It's going to help us just a little bit."