The British team were unable to challenge either Red Bull Racing or Ferrari for speed at the European Grand Prix in Valencia in Spain or at the British Grand Prix at Silverstone, with two fourth places for Lewis Hamilton and one fifth place finish for Button being disappointing results from the two races.
This came after they had looked like Red Bull's closest challengers in the opening races of the season, with Hamilton winning in China while Button came home first in Canada.
McLaren have a poor record at the Nurburgring, the location of Sunday's race, winning only once of the last 11 races held at the circuit, but despite history being against them being victorious this weekend Button is upbeat on his prospects.
"Perhaps we've lost a bit of the momentum we'd built up in previous races, but not much," the McLaren driver said.
"Although Silverstone was disappointing, our pace has been good this year. Sometimes we've been quickest, sometimes we have not."
Martin Whitmarsh, McLaren's team principal, is equally positive that the team will put on a better show in Germany, and is relieved the row over off-throttle exhaust diffusers has been settled, with the use of them now fully legal until the end of the season.
"There has been a degree of uncertainty in recent weeks, with new restrictions placed on off-throttle exhaust blowing, and our entire team has demonstrated enormous passion and commitment as they come to terms with those challenges," he said.
"We missed an opportunity for a podium finish at Silverstone, and that race was a reminder that while we are always pushing to make our car even more competitive, are rivals are doing likewise with their own machinery.
"I'm optimistic that we can move forwards this weekend and be challenging at the front once again."