Michael Ballack has emerged as a doubt for Germany's World Cup opener against Costa Rica on Friday after sitting out training on Monday with a calf strain.
Ballack, who recently joined Chelsea from Bayern Munich, underwent treatment at the team hotel while the rest of the squad were put through their paces by head coach Jurgen Klinsmann.
It is the second injury to have sidelined the 29-year-old since the squad convened for a pre-World Cup training camp in Switzerland two weeks ago, with an ankle injury also curtailing his ability to train.