Ulster flanker Stephen Ferris has been ruled out of Ireland's summer tour to New Zealand with a calf complaint.
Ferris sustained the injury during the Heineken Cup final defeat by Leinster at Twickenham last weekend.
His place in the 29-man touring party will be taken by Leinster back row forward Kevin McLaughlin.
Several positions in the squad will not be confirmed until after the game between Ireland and the Barbarians on Tuesday night.
A further prop, second row, back row and scrum-half will be added before the squad departs for New Zealand.
And the match against the Barbarians at Gloucester will give players the opportunity to prove their fitness and form before coach Declan Kidney finalises his selection for the three-Test series with the All Blacks.
Kidney has so far named three uncapped players - Ulster prop Declan Fitzpatrick, Munster hooker Mike Sherry and winger Simon Zebo.
Ulster's Darren Cave and Dan Tuohy are also included, but young winger Craig Gilroy misses out.
Ulster prop Tom Court has been ruled out with a thumb injury sustained in the Heineken Cup final but Ireland captain Brian O'Driscoll returns after missing the Six Nations as he recovered from a shoulder operation.
Munster second row Paul O'Connell is certain to be added to the squad if he recovers sufficiently from a minor knee operation.
Connacht prop Brett Wilkinson and Ulster flanker Chris Henry are being tipped to fill the other two vacant forwards' positions in the touring party.
Leinster's former Ulster scrum-half Isaac Boss is also set to come in, although Ulster number nine Paul Marshall may come under consideration if Boss fails to recover from a quad muscle injury.
Ulster centre Paddy Wallace has been omitted while Ulster team-mate Tommy Bowe is not available after the winger had surgery on a kidney problem.
Leinster back Luke Fitzgerald is missing with the neck injury which kept him out of the Heineken Cup final.
Ireland will play world champions New Zealand in Auckland on 9 June, with Tests in Christchurch and Hamilton to follow on 16 and 23 June.
"This is a fantastic opportunity for some of the players coming into the squad," said Irish coach Kidney.
"It will be a great learning experience and this is not the time for the faint of heart. We will go there as strong as we can and front up."
Ireland squad: Forwards: Rory Best, Sean Cronin, Declan Fitzpatrick, Cian Healy, Jamie Heaslip, Kevin McLaughlin, Sean O'Brien, Donncha O'Callaghan, Peter O'Mahony, Mike Ross, Donnacha Ryan, Mike Sherry, Dan Tuohy, AN Other, AN Other, AN Other.
Backs: Darren Cave, Gordon D'Arcy, Keith Earls, Rob Kearney, Fergus McFadden, Conor Murray, Brian O'Driscoll, Ronan O'Gara, Eoin Reddan, Jonathan Sexton, Andrew Trimble, Simon Zebo, AN Other.