A team official confirmed that Hairston suffered a mild sprain to his left knee and indicated that the injury prevented him from practicing on Monday.
Hairston is UNC's third-leading scoring through six games, averaging 10.8 points and 4.2 rebounds per contest off the bench. The Greensboro, N.C. native is shooting 35.3 percent from 3-point territory (12-of-34).
Senior guard Dexter Strickland provided more details during his media availability.
"We were doing dribbling drills and the way his knee moved, I was kind of scared because I tore my ACL, so I know what it looks like," Strickland said. "So when he did it, I was kind of worried, but the doctor said there was nothing wrong with his ACL and nothing wrong with his meniscus."
Strickland said that he does expect the second-year guard to be back on the court in a couple of days.
"P.J. is a little dramatic with his injuries," Strickland joked.
UNC announced on Monday evening that Hairston's status for the next game -- against UAB on Saturday - was not yet known.