Defender Mats Hummels is set to miss Germany's second group game against Sweden on Saturday after suffering a minor neck injury in training, coach Joachim Low told his prematch news conference on Friday.
After losing their first match against Mexico, Germany need all three points in order to have their fate in their own hands in the final match against South Korea next Wednesday.
However, their hopes suffered a setback on Thursday when Bayern Munich centre-back Hummels picked up the injury.
"He will most likely not be able to play," Low said. "He craned his neck in training and he's not able to train today. And while we still have some time we will need players who will be able to go into the aerial duels against Sweden, and that's why it won't make a lot of sense, really."
Hummels, however, was still holding out hope he'd be fit to play, writing on Twitter:
All Germany's other players are fit going into the match with the Swedes, who have not beaten the Germans for 40 years and last came out on top in a World Cup match 60 years ago.
"Our two most important weapons are energy and body language," Low said. "That was not the team we know against Mexico. The level of play is still not at a top level at this World Cup. It's a World Cup of dedication and passion, and attitude plays a major role."
Throughout the week there has been speculation in the German media about who Low might drop following the Mexico match, but he maintained that he had not lost belief in his key players.
"The fundamental trust in those players who have been at a top level for three, four years, maybe even longer, won't go away just because of one match," he said.
"It might very well be that someone might not play a match. But they have all been at a high level for years, and we are still up there with the world's best. Why should we question everything after just one match?"
Low added that Germany needed to make "corrections" and be aware of the mistakes that were made against Mexico.
"We must not doubt our style of play," he said. "If we can play to our strengths, we will be good also against teams defending deep in their own half.
"What we will need in attack tomorrow are lads who make deep runs, invest into their running paths. It's about those runs behind which cause problems for the defensive lines."