Bayer Leverkusen sustained a series of injuries after beating third-tier club Arminia Bielefeld in the DFB-Pokal on Wednesday.
• DFB-Pokal review
Leverkusen needed extra-time to win the game 3-2 but victory came at a cost with Omer Toprak, Lars Bender, Michael Rensing and Daniel Schwaab picking up problems.
On Thursday, the club confirmed that defender Schwaab had torn ligaments in his ankle as a result of a Dennis Riemer tackle and that he will be sidelined for at least two weeks.
Schwaab joins Renato Augusto, Karim Bellarabi, Bernd Leno and Czech Republic international Michael Kadlec on the injury list.
Bender was hit by an elbow while Toprak picked up a nasal bone fracture and goalkeeper Rensing hurt his eye, but the trio are all expected to be available for Sunday's match against local rivals Fortuna Dusseldorf.
"We don't have a lot of players right now," Leverkusen coach Sami Hyypia said on Thursday. "Hopefully we don't pick up any more injuries."