Ballack is struggling with a shin injury that he sustained in the game against Hannover on September 11.
Tests on Tuesday have confirmed that the Leverkusen star will be out of action for longer than first expected.
“This is very saddening. However, I hope that Michael Ballack will return to the team for the second half of the season strengthened by his rehabilitation and specific preparations,” Leverkusen coach Jupp Heynckes was quoted as saying on his club’s official website.
