The complaint has initially been diagnosed as a tendon problem, and he is to see another specialist towards the end of this week. However, he is continuing to do light training.
This will give Smith the opportunity to stake a claim for another first team appearence.
Smith said "I was really thrilled to get a chance to play against Brighton and was quite happy with the way I played.
"I have been quite patient because I have been behind Ole, who is a quality keeper with lots of experience, and I have learned a lot from him."
"Now I have got the shirt, I know Ole will want it back, and that kind of competition can only be good for both of us.
"I don't know whether I'll be picked for the next game - that's down to the manager - but there is nothing like playing in front of a crowd."