CHAPEL HILL, N.C. -- His North Carolina teammates don't know when suspended junior guard P.J. Hairston will be on the court for a game this season, but they expect to see a changed player when he does return.

Tar Heels coach Roy Williams said the 6-foot-6 guard earned the right to join the team when practice begins for the 2013-14 season Friday. Williams said Hairston accepted his disciplinary punishment of an additional running regimen.

However, Williams has not decided when to fully reinstate Hairston.

Coach Roy Williams said Thursday there's "no question" suspended guard P.J. Hairston will play for the Heels this season. The question is, when? Ed Zurga/Getty Images

"When I completely decide what it will be, I'm going to tell you, and I'll tell you before the season starts," Williams said at Thursday's media day.

Hairston was not made available Thursday. In a statement, he apologized for "the mistakes that brought such negative attention to the team, the University of North Carolina and my family."

"I know I let a lot of people down, including our fans and all the people who love not just the basketball team but UNC," the statement said. "I will do whatever I can to regain your faith in me and make sure I represent the school and the Tar Heels with respect in the future."

Williams suspended Hairston on July 28 after the player had several offseason incidents, including a June arrest for misdemeanor marijuana possession and driving without a license. A gun was found at the scene, although it was not tied to Hairston. Those charges were dropped after Hairston completed a drug assessment program.

In July, Hairston received a speeding ticket that included an additional charge of careless and reckless driving, which prompted his suspension.

Williams said there was "no question" Hairston, who averaged 14.6 points per game last season, would play this season.

In the meantime, Williams is doling out old-school discipline. Hairston has had an offseason filled with 5 a.m. conditioning runs, and Williams said Hairston has run 18 more days than any other player on the team.

"Some guys would give up; some guys wouldn't take that opportunity," said senior guard Leslie McDonald, who added that Hairston apologized to the team. "… You can tell by his actions -- the way he works hard in the gym, the extra running -- you can tell that he's sincere about everything."

Sophomore forward Brice Johnson said he's noticed a change in Hairston.

"He's just a lot more focused now," Johnson said. "Instead of doing crazy stuff -- he wasn't really doing crazy stuff, but some of the decisions he made weren't as smart as they should be. ... He's starting to make a lot more smarter decisions now."

The NCAA is reportedly looking into Hairston's relationship with Haydn "Fats" Thomas, a convicted felon who rented the 2013 GMC Yukon that Hairston was driving at the time of his first arrest. Williams said he couldn't "speak to what the NCAA is doing, but I know Roy Williams has a tremendous voice in what else is going to be done."

The Tar Heels' season starts with a Nov. 1 exhibition against UNC Pembroke. They open the regular season Nov. 8 against Oakland.