Nelson was injured when he challenged for a header with Jose Fonte in the second half and was taken to hospital.
But manager Bryan Gunn told the club's official website: "Kit man Manny Fowler went with Michael to hospital but we were able to pick them both up and bring them back to Norfolk on the team coach.
"He was badly concussed but he has been given the all clear. We will keep a close eye on him for the next few days."
New signing Simon Whaley scored the only goal when he collected Grant Holt's pass to hit a low shot into the corner.