"The tension is building slowly, we have been working for two years for this moment. It's time to get going," said Lahm
Germany open their Euro 2012 campaign bidding to beat Portugal for the third successive time at a major finals with captain Philipp Lahm insisting his team must show what they can do on Saturday.
The Germans, three-time European champions, eliminated Portugal in the quarter-finals four years ago at Euro 2008 after also beating them in the third place play-off at the 2006 World Cup.
Lahm admits those results will have little effect on Saturday's Group B clash, but a good start is vital with 2010 World Cup finalists Holland and Denmark still to come.
"The tension is building slowly, we have been working for two years for this moment. It's time to get going," said the 28-year-old who took over the captaincy officially from Michael Ballack after the 2010 World Cup.
"We have a great squad, we just need to show what we can do."
Germany flew to Lviv, Ukraine, on Friday with assistant coach Hansi Flick admitting victory is crucial to their chances of surviving the so-called 'Group of Death'.
"It is always important to get a win in the first match especially in a group like ours," he said.
"The next game against the Dutch is probably a step up and we hope we get out of the group as winners.
"It's been called 'the group of death' and I do think it is the strongest in the tournament, we have to be alert from the word go and perform as we know we can."
Last month's shock 5-3 friendly defeat at the hands of Switzerland, on the back of their 2-1 loss to France in February, suggest the Germans have defensive deficiencies for Portugal to exploit.
Coach Joachim Loew looks set to include his midfield general Bastian Schweinsteiger as the Bayern Munich star has recovered from the calf strain he picked up during the Champions League final defeat to Chelsea.
Portugal's greatest weapon is Real Madrid star Cristiano Ronaldo whose haul of 46 Spanish league goals last season was bettered only by Barcelona's Lionel Messi, who finished with a tally of 50.
"It goes without saying we have to defend well and be careful with our tackling around our penalty area," said Flick.
"Ronaldo has some excellent free-kicks, but we have a world-class goalkeeper too."
Per Mertesacker, who surived an injury scare in training on Thursday, has said the German defence must keep a close eye on him.
"We must try at all costs to avoid one-on-one situations with him, because Ronaldo plays a key role," he said.
Ronaldo was effectively subdued by the German defence the last time the two teams met in the quarter-finals of Euro 2008 as Loew's team won 3-2 en route to the final, but says revenge is not an issue.
"I don't like using that term 'revenge' in football, because it's simply a football match, it isn't a war," Ronaldo told uefa.com.
"We want to win, which is obvious, because we want to start the European Championship well."
Portugal coach Paulo Bento has said his side must be brave to beat the Germans, especially after their recent 3-1 defeat to Turkey and last month's goalless draw with minnows Macedonia.
"Against a team like Germany you need to be organised," he said.
"You need to have courage because if you only think about defending, then surely you won't be able to get a good result.
"You have to try to attack them, but in an organised way. Above all we have to be strong, aggressive and cohesive, especially when we lose the ball."