Carlton defender Ciaran Byrne has announced his retirement from the AFL, and has headed back to Ireland.

The Blues' Category B Rookie and Irishman Cillian McDaid has also announced his retirement, and will head back home after failing to register an AFL game.

Byrne made the call last week, and has since played in the IFC final in his homeland, where he suffered a "nasty" leg injury.

Before leaving, Byrne told the club's website heading home wasn't an easy decision to make.

“This decision hasn’t been made lightly, it’s something that’s been on my mind for a while but ultimately I feel the time is right for me to go back home,” Byrne told carltonfc.com.au.

“The Club has been incredibly supportive, managing the best interests of both myself and my family and for that I will always be incredibly thankful and grateful. I will miss the Club, my teammates and coaches and will always be a Carlton person.

“I wish the boys the very best for next season and beyond.”