Reddick, a 6-foot-3, 230-pound linebacker from New Bern (N.C.), has been enrolled at UNC since the second summer semester and participating in preseason practice.
In a press release Friday, UNC announced that Reddick "will not attend the University this fall."
"Kevin is a fantastic young man, and we expect him to be a part of our program in the future," said UNC head coach Butch Davis.
According to sources close to the situation, Reddick, who was initially deemed academically qualified, had to retake the ACT on Monday. His score fell short of the qualifying range.
According to Prunty, Reddick isn't expected to reopen his recruitment.
Reddick was one of the top-rated prospects in the Tar Heels' freshman class and was expected to compete for playing time in the 2008 season.
Rated the No. 12 middle linebacker in the nation by Scout.com, Reddick recorded 189 tackles, eight sacks, six forced fumbles and blocked four punts for New Bern last season, earning first-team all-state honors.