Germany are sweating on the fitness of inspirational skipper Michael Ballack ahead of a visit from Wales on Wednesday.
The midfielder was forced to skip training on Monday as he continues to struggle with a calf problem.
Ballack was on target during a 2-1 victory over Russia on Saturday which left Germany top of 2010 World Cup qualifying Group Four.
However, while his team-mates were put through their paces in Dusseldorf as preparations for the Wales clash intensified, Ballack required physio at the team hotel.
The German Football Federation (DFB) insist the Chelsea man was only left behind 'as a precaution', but refused to comment on whether the injury will rule him out of midweek action.