Following a scan on Monday, Town's worst fears were realised after results showed that the former Plymouth Argyle midfielder had suffered ligament damage in his knee which will rule him out for between four and five months.
Confirming the news Town boss Roy Keane said: "It will be a big loss. He is a battler and he breaks up the play well and gets things going from there."
Norris becomes the second Town midfielder to be ruled out until the new year, with Argentine midfielder Luciano Civelli sidelined until early 2010 after also sustaining extensive knee ligament damage in March.
Click here for a player profile on David Norris