Jenson Button was putting a brave face on his fifth place on the gird for the German Grand Prix, having qualified nearly seven-tenths of a second off Sebastian Vettel's pole time.

Having taken the fight to Red Bull Racing in Turkey - to the point where its rivals clashed while disputing the lead - and seeing team-mate Lewis Hamilton add another victory next time out in Canada, McLaren appears to have dropped off the pace, even though it has managed to salvage podium finishes from both the European and British grands prix.

Ironically, fifth on the grid at Hockenheim was Button's best qualifying performance since Montreal, and left him one place ahead of Hamilton, but the world champion insisted that he was frustrated by the gap to Vettel and a resurgent Ferrari team at the front of the field. Despite that, however, he tried to find reasons to be optimistic for the German Grand Prix as he and Hamilton attempt to defend the top two places in the championship standings.

"I think we can still have a very good race," he insisted, "If you look at the speed traps, you'll notice that we are quite a bit quicker than the two teams in front of us. Maybe that isn't a positive thing in qualifying but, in the race, I think it could help us as long as we can look after the tyres."

In the cockpit, Button admitted that he expected to be higher than fifth on the grid, and it was only discovering the pace of his rivals that contributed to his frustration.

"I was reasonably happy with the lap," he told Reuters, "I thought I'd be a little bit closer to the front when I crossed the finish line, I didn't think I was going to be seven-tenths behind pole position.

"It took a little time for us to get used to the balance of the car [with the blown diffuser] this weekend, but I was pretty happy with my final lap, so I don't know where the extra seven-tenths is. That's the slightly worrying thing - it was a good lap, and I don't really think there was anything else I could've got out of the car."

With McLaren having opted to run its revised diffuser system, however, Button remained optimistic about his chance of adding good points to his tally.

"We've definitely made a step forward with the diffuser - it's still not quite enough in qualifying spec, but, hopefully, we'll see some more performance tomorrow," he insisted, "From fifth on the grid, we can still have a good race, and this is a fun place to go racing. The first lap is usually pretty hectic, so I'll be hoping to pass some cars early on. I definitely think we can get a great result tomorrow."

Despite Button's words, however, team principal Martin Whitmarsh admitted that the diffuser system was still not operating at maximum potential.

"I think we probably have half, or less than half, of what is possible," he revealed, "I'm sure, as races go by, we'll get more from that. Once you've got this concept working, the aerodynamicists can start to work on details of the floor, they can start to work on the exhaust and how it interacts with the wheels and tyres. There is a lot of scope now to make some progress."