McCarthy, who earned his first international call-up as an Eagle in August last year, returns to his grandfather's country of birth to take on Bulgaria and Finland.
The Nations League games will take place on 3rd and 6th September respectively, playing away in Bulgaria and then at home in Ireland to take on Finland.
This means the 29-year-old will meet up with his international teammates on Sunday (30th September), train for two days and then fly to Bulgaria on Tuesday (1st September).
Stay tuned to cpfc.co.uk, the official Palace app and our social media channels for updates!
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