Germany [Images] captain Michael Ballack [Images] has recovered from a minor foot injury and is fit to play in the World Cup quarter-final against Argentina, coach Juergen Klinsmann said on Monday.

Ballack missed training on Sunday morning because of the minor knock and the team's next scheduled training session is not until Tuesday.

"It's all healed. He's perfectly fit," Klinsmann told a news conference.

"Ballack is of great importance to this team," Klinsmann added. "He reads the game well and is prepared to sacrifice himself. He has a key role."

The captain was forced to sit out Germany's opening 4-2 win over Costa Rica because of a calf injury. Since his return to the midfield, Germany have not conceded a goal in beating Poland 1-0, Ecuador 3-0 and Sweden 2-0.

Germany meet Argentina in the quarter-final at the Olympiastadion in Berlin on Friday.