Dutch midfielder Fer missed last weekend's 4-1 defeat to Aston Villa and he will again sit out Saturday's crucial home clash with Stoke.
Canaries boss Chris Hughton admits Fer faces a number of weeks out of action, but is refusing to put a timescale on how long he will be absent.
"It will be a matter of weeks," admitted Hughton. "He's a young lad and he's not somebody who has continuously had this type of injury.
"We're a bit reluctant to put a timescale on it.
"Sometimes the recovery time can be better than what you think."