Football Federation Australia boss David Gallop has described Lucas Neill's angry outburst during Tuesday night's friendly against Costa Rica as 'unacceptable'.

The Socceroos captain was caught on camera reacting angrily to a section of the Allianz Stadium crowd in the second half of Australia's 1-0 win, belligerently asking hecklers 'Why are you f***ing booing?'

The verbal assault has drawn widespread criticism from fans and pundits alike and it appears Gallop is among those who are unhappy with the former Blackburn and West Ham defender.

"The action of swearing and reacting like that to a section of the crowd was unacceptable," Gallop told reporters.

"While that kind of crowd behaviour is not what we want to see, Lucas should have let it slide. In the cool light of the next few days I expect he will realise that."

Despite the condemnation from Gallop, Neill stood by his actions in a press conference on Wednesday.

The 35-year-old said that while it was wrong of him to swear, he would not accept abuse from what are supposed to be the Socceroos own supporters.

"Towards the end of the game I think a few people had some courage juice and they started to boo me and only me when I was on the ball and I can't tolerate that," Neill said.

"I'm Australian coming to Australia to play for Australia and to be booed by Australians, it's unacceptable.

"But what it is, and these guys don't understand, it's detrimental to the team."