Rory Delap is the latest withdrawal from the Republic of Ireland squad for Saturday's final Group Two World Cup qualifier against Cyprus at Lansdowne Road.
Delap suffered a toe injury and had to be substituted after 51 minutes as the Southhampton triumphed 3-1 over Middlesbrough on Saturday.
Mick McCarthy is awaiting reports on the fitness of Coventry central defender Gary Breen and Millwall midfielder Steven Reid, who have both had hamstring problems.
Breen limped out of Coventry's 2-1 victory over Gillingham on Saturday while Reid missed Millwall's goalless draw with Walsall.
McCarthy said: "We will monitor the situation carefully when the squad assemble in Dublin tomorrow. "Only then will I have a proper idea as to whether it might be necessary to call up more replacements."
Earlier he gave a recall to 34-times capped Wimbledon defender Kenny Cunningham as a direct replacement for injured Manchester City central defender Richard Dunne.
Dunne received a hamstring injury in the Dons' 4-0 triumph at Maine Road on Saturday.
McCarthy already has striker Robbie Keane and midfielders Jason McAteer and Mark Kinsella on yellow cards from previous qualifying games, with Cunningham in the same category.
Now McCarthy may decide to keep the quartet in cotton wool for the play-off games against an as yet unknown Asian nation next month.
That could mean a third cap for Newcastle central defender Andy O'Brien who had brief appearances as a substitute against Estonia and Croatia earlier in the year.
O'Brien has been a regular in Bobby Robson's Newcastle side so far this season following his £2million move from Bradford towards the end of last season.