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          Dortmund midfielder Sven Bender out 4 weeks after knee surgery

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            Jan 9, 2015, 02:11 PM ET

            DORTMUND, Germany -- Borussia Dortmund midfielder Sven Bender is out for around four weeks with a knee injury that was operated on Friday.

            The club say Bender underwent meniscus surgery after twisting his knee in training on Wednesday. It did not say which knee was affected.

            Bender, a defensive midfielder, was one of the few Dortmund players to perform consistently well in the club's worst opening half to the Bundesliga since the 1984-85 season.

            Just one goal separates Dortmund from bottom club Freiburg at the halfway stage.

            The 2011 and 2012 champion recently signed Slovenia midfielder Kevin Kampl from Red Bull Salzburg to reinforce the squad.

            Bender's is just the latest injury Dortmund coach Juergen Klopp has had to contend with this season.