The 21-year-old, who did not feature in Wednesday's 1-1 draw with England, sat out training at Malahide on Friday morning with a groin injury, and will return home on Saturday.
Assistant manager Marco Tardelli confirmed Brady's impending departure, which will mean he also misses the friendlies against Georgia and Spain either side of the visit of the Faroes to Dublin on June 7.
Tardelli said: "Robbie has a little problem and I think tomorrow, he will go back home. It's not a very big problem, but it's better he rests."
Goalkeeper David Forde, who had his right knee heavily strapped on Thursday, trained in the gym on Friday, but is unlikely to figure against the Georgians on Sunday, while full-back Marc Wilson has recovered from a hamstring injury.