Button concerned about rivals' pace

"I am, yeah," said Button on his website when asked if he was worried about the pace of his rivals.

"We've seen since the start of the season that the Red Bull has been the car to beat. I've won a couple of races, and so has Lewis, and you could say that, for a few races at least, we perhaps had the quickest race pace, and we were able to make the most of that.

"But Valencia showed us that the opposition never stands still. And a number of teams showed up with some significant upgrades, and even if the results didn't necessarily show it, we became aware of their intent."

He is adamant, however, that McLaren will raise its pace as it continues to push with the development of its car.

"We saw ourselves at Silverstone, that it's not easy to arrive at a track and simply 'switch on' a new package - it requires quite a bit of effort - so I think over the next few races, we're going to see a lot of the top teams further fine-tuning their refinements. So we can't afford to stand still.

"And we're not. I think we've perhaps punched above our weight at the last two races - which is great for us - but we're not standing still."

The Briton said he is optimistic that the rear blown diffuser the team introduced at Silverstone will be ready for the German Grand Prix, despite having to remove it for the British GP.

"At the moment, we're hopeful of taking the blown diffuser to Hockenheim to run it on Friday," he said. "We learnt quite a bit about it from the day's testing at Silverstone, and I hope we'll be in a position to get it working more effectively at the Santander German Grand Prix."

Button, who finished in fourth at the Silverstone race, said his team had made the right call in removing the blown diffuser.

"It's one of those things where, perhaps, you go into it feeling optimistic that it will deliver the required performance step, but, in reality, it's more complicated than that," he said.

"At Silverstone, we had the added complication of a new track configuration that we'd never driven on before. And it was also very, very bumpy, which didn't help us quickly fine-tune the set-up of the car.

"On Friday, we struggled to make the car feel nice - it was just unpredictable and difficult to feel comfortable in. That could have been a set-up issue, but Lewis was reporting exactly the same issues from the other side of the garage, so it quickly became apparent that it wasn't an individual problem, it was something affecting both cars.

"Was it the right decision to go back to the old floor? It was a tough decision, but you've got to look at the result we got on Sunday to say that we made the right call."