James Vaughan is waiting on a knee scan to confirm the length of time he will be out for, after the forward took a knock in Norwich’s 2-1 win over Sunderland at the weekend.
Norwich manager Paul Lambert confirmed the news, but insisted that it is not the same injury that affected Vaughan in 2010.
"His knee is locked which is not a good sign, we'll know more [after the scan],” Lambert said.
"He's really unlucky and is a bit down as you can imagine.
"He just came back from a knee injury, the only thing is it's not the same one as he hurt before, we'll have to wait and see."
Norwich currently sit at ninth on the Barclays Premier League table, and after a difficult start to the season, have now won two matches in a row and are looking to continue their good form.
Despite not having Vaughan for at least the short term future, Lambert was looking at the positives as Nowich prepare to take on Manchester United at Old Trafford this Saturday.
In particular, he had praise for Marc Tiernery, who has come along way from playing for League One side Colchester united just nine months ago.
“Marc's playing consistently well. If you look back at his career he's a hungry lad trying to do well and he's playing at an extremely high level,” Lambert said.
"When you do that, people just expect it, and that's something he's created for himself and that's maybe why he gets overlooked [for praise]."