Grady High School's football team used ineligible players and must forfeit victories from last season, according to penalties assessed by the Georgia High School Association on Tuesday.

GHSA also placed the football program on probation for next season and it won’t be allowed to participate in the 2014 state playoffs.

An Atlanta Public Schools investigation found this month that at least 14 football players used falsified residency documents to attend Grady. GHSA Executive Director Ralph Swearngin wrote that four students violated state eligibility rules.

Atlanta Superintendent Erroll Davis said Tuesday that further investigations have revealed three more players were fraudulently enrolled, meaning nearly one-third of the team shouldn’t have been on the field.

“The travesty here is that 17 ineligible kids played, which means 17 other kids didn’t have the opportunity to play,” Davis said. “This behavior isn’t acceptable and won’t be tolerated.”

The Grady Grey Knights finished with an 8-3 record after losing in the first round of the playoffs Nov. 15. Grady will forfeit all games from the 2013 season in which ineligible students participated.

GHSA also fined the school $1,000 for lack of administrative oversight.

Atlanta Public Schools said in a statement it will work collaboratively with GHSA and that additional penalties may be assessed if further violations are discovered.