Leinster winger Dave Kearney will miss Ireland's tour to Argentina after suffering a knee injury in the Pro12 semi-final win over Ulster on Saturday.
Kearney was a key part of Joe Schmidt's Six Nations-winning squad.
Tommy Bowe is being rested after an injury-plagued season, while Ian Madigan and Gordon D'Arcy are absent.
Munster prop James Cronin, Ulster forwards Rob Herring and Robbie Diack and Connacht scrum-half Kieran Marmion are the uncapped members of the panel.
The squad, which comprises 16 forwards and 14 backs, will depart for the two-Test tour on Sunday 1 June, the day after the Pro12 final between Leinster and Glasgow.
Sean O'Brien is not included after an infection complicated his recovery from shoulder surgery, but Munster wing Simon Zebo is named after being overlooked for the Six Nations championship success.
The first Test will be played at the Estadio Centenario in Resistancia, situated in the north-east of Argentina, on Saturday, 7 June.
The second Test will take place a week later in Tucuman, north-western Argentina, both with a 19:40 BST kick-off time.
Ireland squad: Forwards: Rory Best (Ulster), James Cronin (Munster), Robbie Diack (Ulster), Iain Henderson (Ulster), Chris Henry (Ulster), Jamie Heaslip (Leinster), Rob Herring (Ulster), Dave Kilcoyne (Munster), Jack McGrath (Leinster), Marty Moore (Leinster), Jordi Murphy (Leinster), Paul O'Connell (Munster), Mike Ross (Leinster), Rhys Ruddock (Leinster), Devin Toner (Leinster), Damian Varley (Munster).
Backs: Darren Cave (Ulster), Keith Earls (Munster), Robbie Henshaw (Connacht), Paddy Jackson (Ulster), Felix Jones (Munster), Rob Kearney (Leinster), Kieran Marmion (Connacht), Luke Marshall (Ulster), Fergus McFadden (Leinster), Conor Murray (Munster), Eoin Reddan (Leinster), Jonny Sexton (Racing Metro), Andrew Trimble (Ulster), Simon Zebo (Munster).