Germany captain Michael Ballack has been ruled out for up to six weeks after injuring his knee in Saturday's 2-2 draw against Hannover.

The 33-year-old midfielder had to be substituted after half an hour with what turned out to be a hairline fracture of the shinbone head.  

A magnetic resonance imaging scan in Cologne confirmed the diagnosis on Sunday. 

Ballack, who joined Leverkusen from Chelsea during the summer, had only recently returned to match fitness after recovering from the ankle injury which prevented him from playing at the World Cup in South Africa