AFL Football Operations Manager Adrian Anderson said the AFL had investigated the matter after receiving a report from the match-day interchange steward and had sought responses from both clubs, along with the key match day officials.
Swans player Jesse White went on to the field late in the last quarter after teammate Kieren Jack had replaced Lewis Roberts-Thomson. White headed into the North Melbourne forward line, away from where play was situated, but Sydney had an extra player on the field for some 30 seconds before Darren Jolly, the closest player to the interchange area, was removed from the field. The Swans did not lodge an interchange notice for White.
Anderson said the AFL viewed the matter extremely seriously.
He said it was the responsibility of the club, at all times, to ensure it complied with AFL regulations in regard to numbers on the field and the correct operation of interchange procedure.
The regulations state that all interchanges must be lodged with the interchange steward.
"It is incumbent on clubs to ensure that they do not breach the Laws of the Game and it is entirely their responsibility to ensure their interchanges are made correctly," Anderson said.
"Under both AFL Regulations and the Laws of the Game, a club can face a range of sanctions for having extra players on the ground, including financial sanctions and the loss of premiership points," he said.
Anderson said the AFL would now place all clubs on notice and had determined a financial sanction against the Swans was appropriate.
Anderson noted that several factors, including the Kangaroos not calling for a head count and White not being directly involved in the play, meant the loss of premiership points was not enforced.
Anderson said $25,000 of the sanction would be suspended for a period of 24 months.
