Torquay have informed the Football League that Jake Robinson played against Hereford on Tuesday night despite being unregistered.
The Gulls handed Robinson - on loan from Shrewsbury - his debut however he was not eligible to play.
The League Two club released a statement which read: "Torquay United have informed the Football League of an incident relating to Tuesday night's match with Hereford United at Plainmoor.
"The club was alerted to the fact an unregistered player had taken the field after kick-off and we have voluntarily offered our explanation to the Football League.
"We are now waiting for a response from the Football League and, as such, we will be unable to make any further comment at this time."