Haydn Patrick "Fats" Thomas accepted the deal Wednesday in a Durham County courtroom.
He pleaded guilty to charges of possession of a firearm by a felon, drug possession with intent to distribute and possession of drug paraphernalia from a December 2012 arrest. A fourth charge of maintaining a dwelling to distribute was dismissed.
Thomas received a suspended sentence of 23 to 47 months in jail and must complete 100 hours of community service within the first 12 months of his probation term.
Thomas' name or address appeared on rental records for vehicles driven by Hairston during traffic stops in May and June.
Hairston, 20, was cited twice in a month this summer while driving a rental car linked to Thomas.
The player was originally cited for speeding in May while driving a late-model sports car rented under the name of a woman sharing Thomas' home address.
Less than a month later, Hairston was arrested in Durham along with two passengers and charged with misdemeanor marijuana possession while driving an SUV rented under Thomas' name.
Hairston was suspended indefinitely from the Tar Heels team July 28, hours after his third run-in with authorities -- when police pulled him over for driving 93 mph in a 65 mph zone near Salisbury. He was cited for speeding, and careless and reckless driving while driving a 2008 Acura owned by a friend, Randi Lee Furr.
Hairston was the Tar Heels leading scorer, averaging 14.6 points for the season. He announced in April that he would return for his junior season instead of entering the NBA draft.