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.
