CANBERRA, Sept. 1 (Xinhua) -- Australia's national football team has shocked fans on Tuesday by canceling a public appearance, as a pay dispute with the nation's chief football body continues to escalate.

The Professional Footballer's Association (PFA) said that while the team would be fulfilling its match day requirements, fan engagement activities, along with other "related activity" would not go ahead.

The Socceroos play a World Cup Qualifier in Perth on Thursday, but hastily canceled a public appearance that was set to occur at a major shopping center on Tuesday.

A statement from the PFA said the action was a result of the expiry of the players' Collective Bargaining Agreement (CBA), and Football Federation Australia's (FFA) decision to terminate the Memorandum of Understanding between the PFA and the FFA last month.

"In addition to confirming their participation in World Cup qualifiers, the players also resolved to participate in community, media and charitable work whilst in camp," the PFA statement read.

"However, in the absence of a CBA, the players have elected not to perform any additional work, namely commercial activities and appearances on behalf of FFA."

"In an environment where their rights are being attacked, the players are unwilling to continue to undertake commercial appearances."

The head of Australia's football body, David Gallop, apologized to fans on Tuesday for the actions.

"This action by the PFA will deny many people a rare opportunity to see Socceroo players in Perth," the FFA chief said in a statement.

"We deeply regret that many people will be left disappointed."

The Socceroos take on Bangladesh in Perth on Thursday night.