Germany team manager Oliver Bierhoff has called for a circumspect approach from his side as Euro 2012 edges closer.
Germany, who finished third at the 2010 FIFA World Cup, are considered a big chance of winning the tournament in Poland and Ukraine.
But Bierhoff says the team must relax in training after a series of ‘intense’ sessions, in a bid to avoid injuries.
“You can feel that the fight for the starting 11 has started,” Bierhoff said.
“Yesterday the training must have been very intense, they played five against five and everybody who plays football knows how intense this is with little space and many challenges.
“Now we must slow down the pace and we must not look for risks to provoke with other games or opponents injuries.”
Germany are drawn in Group B, with pool rivals Netherlands, Portugal and Denmark all ranked in the top 10 of the world.
German defender Per Mertesacker knows defeating the Portuguese in their group opener on Saturday will be difficult.
“Portugal has had very good individual players over the past few years,” Mertesacker said.
“When we played against them (in the Euro 2008 quarter-final), they had good players but we fought against them as a team. We managed their individual class, and stuck together as team. That will be the big question for this game.
“I don’t think individual class will be the key. We will have to deal with the strength of Portugal’s team – but we have a lot of quality and want to have the crucial moments on our side.”