McLaren F1 drivers 'waiting' to be overtaken on straights

The Honda V6's current inability to deploy as much regenerated energy as rivals Mercedes, Ferrari and Renault has left Button and team-mate Fernando Alonso facing some large straightline speed deficits in F1 races throughout 2015.

Button believes it will be a similar story at Yas Marina this weekend.

"The race is going to be very tough," he said. "Our deployment is stopping really early on the straight.

"You're sat there waiting for everyone to overtake."

Alonso was ninth fastest in practice two, and fifth in the twisty final sector.

The Spaniard reckoned his pace was partly due to genuine improvement from McLaren, but he still expects to fall back on Saturday.

"Many things could be behind this," he said of the evening session result.

"One is probably the improvements on the car, they keep working and bringing us performance.

"Then maybe we put the super-soft tyres on at the best moment of the session, maybe later than the others.

"Tomorrow we will not be ninth unfortunately, we will be a little bit worse than that.

"But I'm happy with the car today and happy with the progress."

Button was 1.1 seconds slower in 16th place but said his car had been in a very different specification.

"We were trying very different things today, very different set-ups," he said.

"It's all about understanding for next year. I'll be changing my car tomorrow quite a bit.

"I normally enjoy driving around here but today wasn't so much fun.

"We know what to do tomorrow to make it more enjoyable."