Don Givens is waiting for Andy O'Brien to confirm he has retired from international football with Republic of Ireland.
Bolton Wanderers defender O'Brien was recalled to the Ireland squad by caretaker coach Givens for Wednesday's friendly with Brazil.
But O'Brien has not linked up with Givens' squad amid reports the 28-year-old has retired from international football.
Ipswich Town's Alex Bruce has been drafted into the squad as a replacement as Givens waits on contact from O'Brien.
"I haven't been able to make any contact with Andy O'Brien, so I've called in Alex Bruce," confirmed Givens.
Robbie Keane should be fit to play against Brazil after an ankle knock, but Steven Reid is doubtful after missing training with a knee problem.
Givens told the FAI's official website: "Steven Reid sat out today's (session) because he has an injury problem, which is a bit more than we thought.
"Robbie's injury has cleared up and he'll be fine."