"Thomas Mueller slipped and slightly scraped his knee and injured his chin that required some stitches," said team spokesman Harald Stenger.

"But he did not sustain any bone or muscle injuries."

Meanwhile, midfielder Christian Traesch has been dropped from Germany's World Cup squad after suffering an ankle injury in training.

Germany have already lost captain Michael Ballack and first-choice keeper Rene Adler to injury ahead of the finals next month.