MUNICH (AFP) - Bayern Munich midfielder Thiago Alcantara faces another operation after tearing the medial ligament in his right knee for the second time, the German champions confirmed on Wednesday.

The 23-year-old Spain star, who was working his way back to fitness, injured his right knee again on Tuesday in training and will be out indefinitely following surgery.

Thiago initially tore the ligament in his right knee in March, then needed an operation to repair the injury in May, but Bayern had recently announced that he had returned to training.

"What can I say? Of course, I am at the moment profoundly disappointed and pretty desperate. Why is it always me?" Thiago told the FCBayern.de website. "But I will not give up, I will fight again and my turn will come again."