Norwich striker James Vaughan was taken to hospital after being left with a serious facial injury sustained in his side's 1-0 defeat by West Brom.
The forward was caught by Gabriel Tamas' swinging elbow in stoppage time in an incident which saw the Romanian escape any punishment.
Vaughan had been introduced as a second-half substitute having recovered from a knee injury picked up in pre-season but could now face a spell out of action.
Canaries boss Paul Lambert said: "James has gone to see the plastic surgeon at the minute and it is a bad one.
"It has gone straight through his lip and they can't stitch it up, the specialist has got to look at it.
"He had a really nasty gash on his upper lip, which will need a bit of work on it. Hopefully we will sort it tonight and we will have to see how he is."
Lambert was also critical of referee Mark Halsey adding: "I think it was a penalty. I have seen it on tape and he has caught him. It's not great that is for sure.
"The big moments in games you have got to get right and more often than not, we never got that big moment this afternoon.
"The penalty given against us was pretty soft, considering what happened to James."
The Norwich boss did admit that his side had put themselves on the back foot when a mix up between Ritchie de Laet and Declan Rudd allowed Peter Odemwingie to nip in and open the scoring.
"It was a poor goal to lose two minutes in, but we came back really strongly," he admitted.
"However you cannot give teams a goal start, because then you are chasing your tail."