Hamburg defender Slobodan Rajkovic is set for an extended spell on the sidelines after tearing a thigh muscle in his right leg.
The Serbia international had been training with the Under-23s in a bid to overcome an unspecified complaint but pulled up in training after feeling pain in his right leg.
The Bundesliga club revealed on their official website that the former Chelsea youngster faces two to three weeks out.
"For Boban I'm really sorry. He has done so much and is now injured again," head coach Thorsten Fink said.