Both players had to be replaced ahead of schedule in Hoffenheim's 3-1 victory over Hannover on Friday, reports Xinhua news agency.
On Saturday, further examination revealed that both players will be sidelined for the rest of the season, the club declared.
Winger Gnabry sustained an adductor injury whereas midfielder Demirbay suffered a capsular tear in his right ankle.
Hoffenheim are fourth in the standings. They clash with newly-promoted Stuttgart and third-placed Borussia Dortmund in the last two rounds of the Bundesliga season 2018.
(This story has not been edited by Social News XYZ staff and is auto-generated from a syndicated feed.)
