Miller, 33, will be available for City's home game against Central Coast Mariners on Sunday after joining under Football Federation Australia's National Team Replacement Player rule, according to a club statement.
The former Manchester United and Celtic midfielder will be welcome cover for the absent Aaron Mooy (Socceroos), Stefan Mauk (Olyroos), Jonatan Germano (hamstring) and Massimo Murdocca (groin).
City's international marquee Robert Koren (calf) is yet to appear for the club.
Miller boasts plenty of A-League experience after starring during two seasons with Perth Glory, before winning the title at the Roar last season.
He was released by the reigning champions late last month, later claiming he demanded a release after being dropped without an explanation by head coach Mike Mulvey.
The former Manchester United and Celtic midfielder will be welcome cover for the absent Aaron Mooy (Socceroos), Stefan Mauk (Olyroos), Jonatan Germano (hamstring) and Massimo Murdocca (groin).
City's international marquee Robert Koren (calf) is yet to appear for the club.
Miller boasts plenty of A-League experience after starring during two seasons with Perth Glory, before winning the title at the Roar last season.
He was released by the reigning champions late last month, later claiming he demanded a release after being dropped without an explanation by head coach Mike Mulvey.