The 23-year-old landed himself in hot water in the 63rd minute of the Brumbies' big win over the Bulls in Pretoria a fortnight ago - shown a red card after headbutting Matthys Basson.
The sendoff came with the match precariously poised and while ACT went on to claim a season defining win, Faingaa can't makes the same mistake against Ireland, should he earn a debut.
The hit first, think later approach to his game is exactly why Faingaa is in the frame for a debut but he knows the aggression he brings to the side must be controlled.
"I never back down from anything," Faingaa told RUGBY.com.au.
"I know I have to manage my discipline and manage my emotions.
"I need to control that but I'm never going to back down from anything like that."
Faingaa is fighting for a start with fellow former Sydney garbage man Brandon Paenga-Amosa and the Brumbies rake has declared himself ready for the rigours of Test rugby, should coach Michael Cheika call his name when the team is revealed to the public on Thursday.
"Yeah, 100 percent," Faingaa said when asked if he's ready to play Test rugby.
"The boys playing Super Rugby have helped me a lot - they've helped me build my game.
"Whether Cheik picks me or not I'm not really sure but I'm just here to help the team get better."
Faingaa credits fellow Brumbies hookers Josh Mann-Rea and Robbie Abel with giving him the tools to succeed at Super Rugby level, having made the move from Sydney to Canberra at the end of last year.
The move quickly paid dividends, drawn into the Wallabies squad prior to the breakthrough Bledisloe Cup win in Brisbane.
"When I found out I had the opportunity to go down to Canberra I thought it was a good time to make a move," he said.
"Lineouts, scrummaging, stuff off the field with recovery - they've helped heaps.
"Especially Bongo - it's unfortunate about his injury but he's still around and giving me tips and working with me on my game.
"I had no idea and no intentions, really, of playing for the Wallabies at that time.
"I was just doing my best for the Vikings and hoping for a strong preseason at the Brumbies.
"When (Cheika) called me in it shocked me."
Now Faingaa is within touching distance of a first Wallabies cap, a childhood dream has become reality.
"It means a lot," he said.
"It's every kid's dream that plays rugby to pull that gold jersey on and just to be part of this squad means a lot to me.
"Just with how far I've come in rugby, it means a lot."