The suspended deduction comes after Western Sydney's self-imposed closure of their active support area for the club's next match against Perth Glory. 

The suspended punishment will be enforced until the end of the 2018/19 A-League season, including any finals matches.

The potential deduction refers to "any serious incident" that occurs in or around a Western Sydney Wanderers match. What constitutes a serious incident is left to FFA's discretion.

Head of the A-League, Greg O'Rourke, said the club commend the action already taken by the club, but that their fans had "crossed" a line.

“We encourage active support and the atmosphere it brings to our game,” said O’Rourke.

“When done well and within acceptable community standards it is truly a spectacle like none other and a reason for many general sports fans to attend and witness first-hand the vibrant and inclusive experience.

“However there is a line and last Sunday night we saw that line crossed with the illegal use of flares and also anti-social behaviour from a very small minority.

“The images captured and shared many times over move from enhancing the club and football’s brand to damaging it. This behaviour is not acceptable and will not be tolerated.

“We commend and support the action taken by the club and will continue to work with them to create a safe and enjoyable environment for all our fans and the image of the game."

The club escaped a fine, which have previously been in the region of $50,000. Western Sydney have seven days to appeal FFA's decision.