Hamburg SV's Dutch defender Joris Mathijsen faces a period out after he picked up an ankle injury during an international friendly match against Turkey in midweek.
Mathijsen returned to Hamburg with his leg in plaster and will have to wait some days for further tests to determine the length of his absence.
"At the moment his leg is still too swollen to do anything," club spokesman Joern Wolf told reporters. Hamburg play away at Hanover on Saturday.
Injured Germany and Bayer Leverkusen captain Michael Ballack is on track to return after the winter break with the 34-year-old midfielder also hoping to help his team challenge for the Bundesliga title.
"The crutches are gone and that is a big step. If we are all healthy then we can launch an attack for the top spot," he told the Bundesliga website.
Ballack, who also missed the World Cup this summer due to another injury, has not played since mid-September following a fractured shinbone. Leverkusen are in second place, seven points off the top after 12 games.
Hoffenheim's Nigerian striker Chinedu Obasi will need to undergo surgery in his left shinbone after the nagging injury he picked up during the World Cup has not healed properly, the club said.
The 24-year-old, who has only played four times this season, will be operated on next week and will be out for an estimated three months.
