Kevin Doyle will miss the Republic of Ireland's crucial Euro 2016 qualifier with Scotland at Celtic Park on Friday after pulling out of the squad with a groin injury.
The Crystal Palace striker will return to his club for treatment on the injury but no replacement will be called up at the current time.
The Irish squad now stands at 27 players ahead of Friday's game in Glasgow.
Meanwhile James McCarthy continued to be assessed after he complained of a tight hamstring following Everton's 1-1 Barclays Premier League draw at Sunderland on Sunday.
McCarthy is manager Martin O'Neill's biggest doubt ahead of Friday's Euro 2016 qualifier against Scotland at Celtic Park.
He and full-back Stephen Ward headed for the gym as their team-mates warmed up at Gannon Park in Malahide with midfielder Glenn Whelan among them just weeks after fracturing a bone in his leg during last month's draw in Germany