Hertha Berlin will be without Germany Under-21 star Pierre-Michel Lasogga for Thursday's relegation play-off against Fortuna Duesseldorf with the striker out for six months after tearing the cruciate ligament in his right knee.
The 20-year-old limped out of Saturday's 3-1 home win over 10-man Hoffenheim and the extent of the injury was only confirmed later.
Having finished 16th in the Bundesliga, Hertha host Fortuna at Berlin's Olympic Stadium in the first-leg of their play-off for a place in Germany's top flight with the return leg in Duesseldorf on Tuesday May 15.
"I knew straight away that something was seriously wrong," said Lasogga.
"But I will be back, without question.
"Now the boys have to follow this through for me."
Hertha finished the Bundesliga season 16th after their dramatic win against Hoffenheim thanks to two goals from Tunisia midfielder Anis Ben-Hatira.
It gave them a life-line after Cologne were relegated following Saturday's 4-1 defeat by Bayern Munich.