Nugent, who scored his seventh goal of the season in the 2-2 home draw against the Reds, had to be substituted during the second half of the match on Saturday.
The Foxes' leading scorer is still suffering with a severely stiff neck and is currently a doubt ahead of the visit of Ipswich at the weekend.
"We have to see how he is over the next few days. We don't know the extent of it yet," said Leicester manager Nigel Pearson.
"It was a shame because he and Martyn Waghorn were a handful against Forest. It would be a shame to lose him because he has been playing very well."