Dortmund's Ryerson and Moukoko out for rest of year, teenager Brunner in squad
Brunner, a forward, was voted player of the Under-17 World Cup earlier this month as Germany lifted the trophy.
"Defender Julian Ryerson suffered a ligament injury in the away game at Stuttgart (for the German Cup) on Wednesday and will not be available for the coming weeks," the club said in a statement.
"Forward Youssoufa Moukoko will miss the remaining matches of the year due to a muscle injury."
Borussia Dortmund are in fifth place in the Bundesliga, 10 points off leaders Bayer Leverkusen with three matchdays remaining before the league breaks for the winter on December 20th. It resumes on January 12th.
The Ruhr Valley club has already qualified for the Champions League knockout stage and faces Paris St Germain in their last group match next week.