HAWTHORN have been fined $7500 by the AFL for fielding an extra player during the fourth quarter of last Saturday night's NAB Cup match against Adelaide at AAMI Stadium.

The player in question, Brent Guerra, was due to start the quarter on the bench, but played the first four minutes of the term before the error was realised.

During his time on the field, Guerra gathered two kicks and also took a kick-in following an Adelaide behind.

After being contacted by the AFL during the week over the incident, the Hawks acknowledged the error and offered a full written response outlining how the incident occurred.

Under the AFL regulations and laws of the game, a club can face a range of sanctions for having an extra player on the ground.