Schalke 04 paid the price for reaching the Champions League's knock-out phase with captain Benedkit Hoewedes and midfielder Julian Draxler to miss their remaining two league games of 2013.
Centre-back Hoewedes tore his right hamstring in Wednesday's 2-0 Champions League win over FC Basel, while goal-scorer Draxler tore his left hamstring and the pair will sit out Sunday's home match against Freiburg and the away trip to Nuremberg on December 21.
Japan defender Atsuto Uchida should be fit to face strugglers Freiburg having suffered a cut leg which had to be stitched up after the game.
"We have a heavy price to pay for the win," said Schalke's under-fire coach Jens Keller, who has been told a decision on his future will be made over the winter break.
Both Draxler and Hoewedes are expected to return when the Bundesliga resumes at the end of January with Schalke to discover their last 16 opponents when the draw for the Champions League is made on Monday in Nyon, Switzerland, at 1200 local time.
Schalke are sixth in the Bundesliga, but are 17 points behind leaders Bayern in the league table after some erratic form and have been knocked out of the German Cup.