Jonathan Walters and Daryl Murphy will return to their respective clubs and won't feature in Ireland's upcoming Euro 2016 friendly against Slovakia on Tuesday.
Walters, who was this month named the Ireland's Men's International Player of the Year, has failed to recover from a hamstring injury.
Murphy, meanwhile, picked up a knock in Ireland's 1-0 win over Switzerland on Friday night. The Ipswich striker came on to replace Kevin Doyle, who was withdrawn early in the opening half after sustaining a nasty gash on his leg.
Robbie Keane is unavailable for this Tuesday's clash with a knee injury, meaning that Southampton striker Shane Long is the only fit striker in the squad.