Concordia declared the eligibility violation to both the Canadian Interuniversity Sport and the Réseau du sport étudiant du Québec, which governs varsity athletic in the province.
The school said an administrative error allowed the player to appear on the team.
As a result, Concordia had to forfeit its season-opening win over to the Bishop's Gaiters and another victory to the St. Francis Xavier X-Men.
The school's standing dropped to 0–6 after the sanctions were applied.
The RSEQ announced the sanctions but did not name the offending player.