It has now been confirmed that he will not be fit to play again until next season.
Tyson missed the start of this campaign with a similar injury, which kept him out of action until November.
"Nathan has ruptured the medial ligament in his left knee again so he is out for the season," said Forest boss Colin Calderwood.
"Although it is the same knee, it is a completely new injury and the challenge he took on Monday was enough to severely tear the ligament."