Vince Grella's two-footed tackled marred the Socceroos 2-1 win over New Zealand, and captain Lucas Neill is concerned the team's aggressive style could be costly at the World Cup.
Any similar indiscretion will damage the Socceroos heavily in next month's World Cup finals in South Africa.
"It's a lesson for us," conceded Socceroos captain Lucas Neill.
"Our passion and commitment is great, but we've got to be very careful because we might find ourselves without key players in key periods of a game and for the rest of the tournament."
"We've got to make sure we are fully disciplined going into the World Cup."
Grella admitted he went in "a little bit too hard" after New Zealand took a deserved 1-0 lead in Monday night's World Cup farewell match at the MCG.
"It was probably not needed in a friendly game," he said.
"But it's part of football and I take full responsibility for what happened."
Bertos must have thought he was being targeted because within four minutes he was hit by another shocking tackle from Tim Cahill - late and studs-up like Grella's though this time one-footed.
The All White was sent flying in the air and had to be stretchered off.
Fortunately he sustained no lasting damage, but his World Cup could have ended right there.
"It probably could have, but at this stage it's not," a relieved Bertos said later.
"I'm pretty thankful.I didn't rate shin pads at the start of my football career, but after that thank God I am wearing them."
Bertos did his best to be diplomatic about the crude challenges.
"I couldn't really tell what happened, to be honest," he said.
"I was just going for the ball in both of them and felt some contact on my leg. The boys are telling me they were strong challenges but I don't know what to say, man."
Socceroo coach Pim Verbeek felt no need to tiptoe around the issue, and castigated his players for their recklessness.
"I'm going to tell them it's unacceptable," Verbeek said.
"You cannot afford to go into any game and make tackles like that. In the World Cup, it's probably two red cards. I can only give compliments to New Zealand that they behaved themselves."
"They were very professional. My players were not."
Verbeek considered taking Grella and Cahill off immediately but decided instead to substitute them at half time.
New Zealand captain Ryan Nelsen revealed the American referee said the Grella tackle probably deserved a red card but "because it was a friendly he didn't give it".
Nelsen regularly sees the best and worst of his combative teammate at Blackburn in the English Premier League.
"I see Vince do those tackles week in and week out, so I'm not really surprised," he said.