Portland High has forfeited its football victory over Deering on Sept. 12 because it used an ineligible player.

Portland Athletic Director Rob O’Leary said a paperwork issue concerning a student-athlete transferring from Deering to Portland resulted in the player being ineligible.

“It was an administrative mistake,” said O’Leary, who came from Massachusetts this summer to take the job as athletic director.

The principals at each high school and the Maine Principals’ Association must approve a transfer. O’Leary said a review of the paperwork this week indicated the MPA had not signed off on the transfer. O’Leary indicated it was an oversight and reported it to the MPA.

The player, whom O’Leary would not identify, played the final minutes of the game won by Portland, 42-14. He did not participate in any other game.

Portland players went into Friday night’s game with Lewiston at Fitzpatrick Stadium not knowing of the forfeiture. O’Leary said he would tell the team after the game, which Portland won 55-6.

Portland is 4-3 and plays South Portland next week in the traditional “Battle of the Bridge” game before the Eastern Class A playoffs begin.