Play was halted for around eight minutes after the Scotland international clashed heads with United defender Rafael in the second half of the Canaries' 4-0 defeat at Old Trafford.
Manager Chris Hughton said: "He's gone to a local hospital.
"I think that is very much a precaution, he was out for a period of time. It is very much concussion.
"He has also taken a whack in the incident itself so they will have a look at that and X-ray that just to make sure there is nothing broken.
"But by the time he was on his way out he was awake and aware of what was happening around him.
"Whether he will he kept in overnight or not, I don't know."
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