Germany captain Michael Ballack did not complete his first training session on the way back from injury, two days before the hosts open their World Cup campaign against Costa Rica.

Training was closed to the public and to media. The German Football Association announced that Ballack had left the session early in a brief statement.

Ballack suffered a strain to his right calf in Germany's 3-0 win over Colombia on June 2nd.

The player and coaching staff have insisted all along that the injury was not serious but time is now running out for him to make the curtain-raiser in Munich on Friday.

"The medical department is working flat out and Michael Ballack is making progress in his recovery," a German Football Football Association spokesman told reporters earlier today.

Germany, the hosts and three times World Cup winners, also play Poland and Ecuador in Group A.