In stoppage time Vaughan was flattened by a stray elbow from Gabriel Tamas at a corner, an incident which was missed by the referee, but could have brought a red card as well as a chance of redemption for the home side from the spot had it been seen as deliberate.
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 the lip and they can't just stitch it up, the specialist has got to look at it.
"He had got a really nasty gash in 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 added: "I think it was a penalty. I have seen it on tape and he has caught him. It is 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."