North Carolina State linebacker D.J. Green was ruled ineligible by the NCAA for next season and says it's because he took a banned substance.

The university announced Tuesday that Green would not be eligible for the 2012 season, but would still be allowed to practice with the team. Green released a statement through the school to explain what happened.

"During the offseason, I wanted to gain weight so I took a supplement that someone from home gave to me," Green said. "I wasn't responsible enough to check with our coaches to make sure that it was something legal and now I'm paying the consequences.

"I apologize to my teammates, my coaches and to all the Wolfpack fans and hope that other players out there learn from my mistake. Even though it breaks my heart that I won't be able to play next year, I will work hard every day in practice to help try to make my teammates better."

Green, of Macon, Georgia, tied for ninth on the team with 28 tackles despite playing in just seven games this past season. He also had one sack and one interception.