Defender Omer Toprak will miss Bayer Leverkusen's Champions League trip to Atletico Madrid on Wednesday.
Toprak, who joins Borussia Dortmund in the summer, hurt his ankle in Friday's 1-1 draw with Werder Bremen in which he also missed a late penalty.
"Omer Toprak suffered an ankle injury and he will miss the Champions League match against Atletico Madrid," a statement on Leverkusen's official website read.
Leverkusen travel to Madrid attempting to overcome a 4-2 deficit from the first leg.
The Bundesliga side will also be without right-back Benjamin Henrichs, who is suspended, and Germany centre-back Jonathan Tah, who has a muscle injury.
But goalkeeper Bernd Leno "will probably be available" despite needing surgery after rupturing a nasal cartilage in a collision with Bremen's Gebre Selassie.
Toprak's penalty in that match was Bayer's fifth unsuccessful attempt from six spot-kicks this season and sporting director Rudi Voller said: "You can't believe it.
"We could easily have 10 points more by now. Let's have hope for the next penalty."