The ex-Tottenham full-back started the season as Newcastle's right-back but injury has ruled him out since the third game of the campaign.
He is due back, for contention at least, for the Liverpool match next week.
He played 44 games for the Republic of Ireland and he says "it was a great honour to represent my country".
Carr was linked with a move to Celtic last season and it is thought he wil be available in the January transfer window.