Dortmund's Hummels out with ankle injury
The injury means Hummels will also most likely to miss Germany's 2014 World Cup qualifiers against Kazakhstan on March 22 and 26.
Germany international Hummels, a stalwart in the Dortmund defence, suffered a partial ligament tear when he twisted his right ankle and was taken off at half-time on Saturday.
"Mats Hummels will be out for several weeks," the club said, adding more information about the duration of his absence would be provided later.
Second-placed Dortmund, 20 points behind leaders Bayern Munich in the Bundesliga, have advanced to the last eight of the Champions League after beating Shakhtar Donetsk 5-2 on aggregate earlier this week.