Boss Stuart Gray said: "Mark's gone back to Wolves and he will have a scan on his knee.
"Fingers crossed it won't be a cartilage problem but you know it might be serious because Mark Little doesn't come off for nothing.
"We'll find out later how serious it is but he won't play against Swindon or Leicester.
"He was in a lot of discomfort when he came off and his knee stiffened up."