Paul Sherwin, the public information officer for the Durham County Sheriff's Office, said Hairston, 21, was issued a summons on Monday but will not be arrested.
Hairston's court date is Aug. 8.
"If two people get into a fight in North Carolina and there is no serious injury and is not witnessed by an officer, our hands are tied," Sherwin said. "We don't charge people in [unwitnessed] fistfights. They have to file a report with the magistrate office."
Kentrell Barkley, a 6-foot-5, 190-pound rising senior at Northern Durham High School, says in court documents that Hairston "punched him twice in the head" during a heated basketball game Sunday at the Durham YMCA.
"We were playing open gym and I was running up the court and he hit me in the forehead with his fist," the 17-year-old Barkley told ESPN.com on Sunday. "I walked up to him and asked him what happened, and then he hit me again in the neck."
Hairston's agent, Juan Morrow, confirmed to ESPN that his client, selected 26th overall in last month's NBA draft, threw a punch at Barkley. However, Morrow said it was in retaliation.
"The pickup game got heated, the kid swung at P.J. and P.J. swung back," Morrow said. "P.J. did not go out and beat up a little kid like some people want to make it out to be."
Hairston issued an apology to the Hornets organization and fans for "creating this distraction" and for "any embarrassment that I have caused." He refused, however, to comment on the alleged incident, other than a tweet on Monday:
"Believe none of what you hear and half of what you see" #wisdomfrommymother
- PJ Hairston (@Mr_Hairston15) July 7, 2014Barkley's guardian Rich Phillips told The Associated Press that Barkley has a knot on his forehead from one punch. Phillips said he has not hired an attorney and the incident isn't about money.
"This is about doing the right thing and Kentrell feeling like he was violated," Phillips said. Hairston "did this kid wrong. Kentrell is 17 years old, and what happened just isn't right."
Barkley said that after he was hit the second time, several people broke up the altercation as the pair stood face-to-face. Barkley said that Hairston and a friend left before the local police arrived.
Barkley said he had never met Hairston before the incident, although he was aware of who he was from his career at North Carolina.
Phillips' son, Vince, said he was at the Durham YMCA shortly after 5 p.m. Sunday when the game began to get heated. He said Hairston became annoyed after his team had lost several games in a row to Barkley's team.
Vince Phillips said Hairston dribbled down the court with his left hand and punched Barkley with his other in the head before driving to the basket.
"That's when KB came up to him and said, 'What'd you do that for?'" Phillips said. "Then P.J. cocks his arm back and hits KB in the neck."
The two were quickly separated before Barkley could retaliate, according to Phillips.
Barkley, a regular at the Durham YMCA, agreed with his friend's account of the story. "It took me by surprise," Barkley said. "It wasn't like me and P.J. had any beef with each other."
Sherwin said Durham police responded to the incident.
The Hornets were contacted by Morrow and said they're looking into the matter.
ESPN.com's Jeff Goodman and The Associated Press contributed to this report.