Herrington, 18, became the youngest Socceroo to start at a World Cup in Thursday's crunch 0-0 draw with Paraguay.
"Unreal. I can't really describe it, but it means everything," Herrington said.
The young central defender, starting on the left side of a back three, was completely unflappable, with clean passing on the ball, strong work in the air and some crunching tackles.
In the process, he gave coach Tony Popovic clearly some food for thought ahead of next week's round-of-32 game in Dallas.
"The age didn't matter to us. He deserved to play, he was ready to play," Popovic said.
"He's probably frustrated he didn't get minutes against the US, which I love to see - and today he was outstanding.
"He is a special talent and ... it's why he was selected in the squad, not to just make up the numbers.
"And again, we trusted this talented young man in the most important game of the three."
Herrington had to wait his turn and observe the opening two matches.
On Thursday, he got simple advice from Popovic: "just go do my thing."
"He said I deserve to be here, so everyone's got my back - 'just go have fun, go enjoy the moment and embrace being in the World Cup'," Herrington said.
"I loved every minute."
Skipper Harry Souttar played alongside Herrington in a back three that were rarely seriously troubled.
"You wouldn't think that's his first World Cup game. The guy was absolutely composed, calm," Souttar said.
"I could go on all night about these young lads that have just taken everything in their stride and just put on performances like that."
Veteran defender Milos Degenek said Herrington "played like it was his fourth World Cup."
Fellow young gun Nestory Irankunda is a long-time close friend of Herrington and was delighted for and "super proud" of the teen.
"Today, before the game, I just told him 'stay calm, do your thing' because he's so talented," Irankunda said.
"I feel like this is just a glimpse of what he can do ... and he can just get better from here."
Colorado Rapids defender Herrington has already attracted attention from several big clubs, including Barcelona, but is putting it back of mind.
"I just told him to stay away from it," Irankunda said, while noting Herrington had soaked up advice from senior players.
"Obviously I'm still young, but I still treat him like a little brother ... I try to keep him under my wing and help him out as much as I can."
Defender Alessandro Circati added: "His future's in his own hands, no one else's hands, and that will go on and determine how far he wants to go and what he wants to do."
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