Damien Duff has been ruled out of the Republic of Ireland's Euro 2012 qualifier against Macedonia on 4 June with an Achilles tendon injury.
The Fulham winger will have an operation next week and is expected to out of action for six weeks.
Manager Giovanni Trapattoni is already without the suspended Richard Dunne and he has fitness worries over Kevin Doyle, Sean St Ledger and Darren O'Dea.
Midfielder Wes Hoolahan has failed to earn a recall to the squad.
Hoolahan has been omitted from the panel despite helping Norwich win promotion to the Premier League.
The former Blackpool midfielder was not among a provisional 33-man panel for the Republic's three summer fixtures.
Northern Ireland and Scotland are the opposition in Dublin on 24 and 29 May in the Carling Nations Cup before a Euro qualifier in Macedonia on 4 June.
Versatile Wolves man Stephen Ward is the only uncapped player in the squad.
Hoolahan, whose only cap came in 2008, lost out to more established midfield names.
Striker Caleb Folan has been named after scoring two goals in his first five games in Major League Soccer with the Colorado Rapids.
The Republic beat Wales 3-0 in their opening Nations Cup game in Febuary.
"This is a tournament which we want to win," said manager Giovanni Trapattoni.
"More importantly, the remaining fixtures will give us a good opportunity to spend some extra time together as a squad in preparation for the Euro 2012 qualifier agaimst Macedonia."
Republic of Ireland squad: Given (Man City), Westwood (Coventry), Forde (Millwall); Dunne (Aston Villa), O'Shea (Man Utd), O'Dea (Ipswich), St Ledger (Preston), Foley (Wolves), Delaney (Ipswich), Clark (Aston Villa), Coleman (Everton), Kilbane (Huddersfield), Kelly (Fulham), McShane (Hull); McCarthy (Wigan), Whelan (Stoke), Wilson (Stoke), Gibson (Man Utd), Andrews (Blackburn), McGeady (Spartak Moscow), Fahey (Birmingham), Lawrence (Portsmouth), Treacy (Preston), Hunt (Wolves), Ward (Wolves); Keogh (Wolves), Stokes (Celtic) Folan (Colorado Rapids), Walters (Stoke), Keane (West Ham), Doyle (Wolves), Long (Reading).