Moritz Leitner has been ruled out for the rest of the Premier League season with a hernia problem.
Daniel Farke confirmed at his pre-Brighton and Hove Albion press conference that the Canaries midfielder requires surgery on the issue and therefore miss the remainder of the campaign.
Coming out of the Arsenal defeat on Wednesday, there are no new injury concerns ahead of Brighton.
City will be boosted by the return of Timm Klose who missed Wednesday through suspension.
Farke also provided an update on the fitness of Sam Byram and Christoph Zimmermann.
"With Sam, it looks alright. He's on the right path but it will be 1/2 weeks whether we know if he needs surgery.
"The injections are working with Christoph, he's back on the training pitch. He may return to team training before the end of the season."