Borussia Dortmund midfielders Sebastian Kehl and Sven Bender will miss the defending champion's Bundesliga game at Hoffenheim.
Dortmund coach Juergen Klopp says both players are definitely ruled out of Sunday's league game but could return for Wednesday's German Cup match against Hannover.
Kehl is laboring with a knee injury, while Bender's performances have dipped since breaking his nose in the Champions League last month.
Defenders Marcel Schmelzer and Lukasz Piszczek missed Friday's training session with minor knocks but are expected to train normally on Saturday.
Dortmund was 14 points behind league leader Bayern Munich ahead of the last round of games before the winter break.