At halftime of Saturday's Rocky Mountain clash versus CSU, Colorado's two-way player was removed.
Late in the first quarter, Rams DB Henry Blackburn delivered a dirty shot to his abdomen.
Hunter was rushed to the hospital after returning to the game in agony.
Hunter's absence from Colorado's starting lineup for a few weeks was confirmed by Deion Sanders in his postgame news conference.
The future days would provide more information, he added.
It is a serious setback for the Buffaloes as they begin the Pac-12 campaign in a difficult stretch.
In CU's unexpected victory at TCU, Hunter was the hero. a multifaceted game-changer right away on the field.
He had two receptions for 21 yards when he left the Rocky Mountain Showdown.