Sydney defender Aaron Calver will not press charges after a Western Sydney Wanderers fan slapped him on the face at the conclusion of the Sky Blues' 4-3 win at Parramatta Stadium.
But the culprit is almost certain to cop a very lengthy ban from attending any further matches by Football Federation Australia, which has previously issued several fans with five-year bans for anti-social behaviour.
In a separate incident two Sydney FC supporters were left hospitalised, one with a broken leg and the other with a broken wrist, after leaving the stadium.
Several flares were also lit, with at least one being thrown towards the pitch, which is likely to result in multi-year bans for those involved.
FFA is looking into all incidents.
There was no lack of action on the pitch in the seven-goal thriller which was decided by a late Terry Antonis winner.
But a brilliant A-League spectacle was somewhat tarnished by poor fan behaviour.
"All fans need to just take a chill pill to be honest," said Sydney FC CEO Pignata.
"We all want to support our teams win, draw or lose but after that let's get back to the world we live in.
"It's up to the FFA, they'll deal with it so I'll leave it to them to decide what needs to be done."
Pignata said Wanderers CEO John Tsatsimas had called him to also express his disappointment.
Asked if the only way fans would take notice was to punish Western Sydney, Pignata replied: "I'll let you ask John Tsatsimas and the FFA that. I'm not going to answer that."
Calver had been dropped for the match in favour of Sebastian Ryall and was watching from a players' box high in the stands.
The 19 year-old was making his way to the dressing room to celebrate with his teammates when he was assaulted by a Wanderers supporter, who was swiftly apprehended by security.
Pignata revealed that while Calver was "shaken up" by the incident he didn't intend to file a formal complaint to police.
The other altercation occurred as three Sydney FC fans made their way from the stadium to Parramatta train station and were allegedly set upon by a group of up to 30 men.
One of the injured supporters is still in hospital facing an operation on his leg. A second was discharged with a broken wrist.
