Andy Reid, Rob Elliot and Kevin Doyle has all withdrawn from the Republic of Ireland squad to take on Serbia in Wednesday's international friendly at the Aviva Stadium.
Reid, who has been in fine form for Nottingham Forest, underwent surgery on a hernia on Friday that is expected to keep him sidelined for up to six weeks.
"Unfortunately we've lost Andy to a hernia," confirmed Forest boss Billy Davies. "He'll be having an operation this week, but I'd expect him to be out for around four to six weeks after that."
Kevin Doyle has been ruled out with thigh injury, while Rob Elliott misses out with a knee injury.
There are currently no plans to call up any replacements to the squad at the moment.
Republic of Ireland squad: David Forde, Darren Randolph, Richard Keogh, Marc Wilson, Seamus Coleman, John O’Shea, Alex Pearce, Stephen Kelly, Damien Delaney, Richard Dunne, James McCarthy, Ciaran Clark, Stephen Ward, Glenn Whelan, Paul Green, Aiden McGeady, Anthony Pilkington, James McClean, Stephen Quinn, David Meyler, Wes Hoolahan, Shane Long, Daryl Murphy, Jon Walters, Anthony Stokes, Simon Cox.