The 35-year-old sustained the injury in training, adding to a lengthy list of absentees for outgoing coach Jurgen Klopp.
Neven Subotic will also miss Saturday's Bundesliga clash with Paderborn with a back problem, while five other players are doubts after being unable to train on Thursday.
Jakub Blaszcykowski, Sven Bender, Erik Durm, Kevin Grosskreutz and Marco Reus all missed the session, and Oliver Kirch, Nuri Sahin and Lukas Piszczek are definitely sidelined.
So bad are Dortmund's injury problems at the moment, that Klopp had to refer to a list on his mobile phone during a pre-match press conference.
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