Ian Keatley was a surprise omission from Ireland's 45-man training squad named ahead of a series of World Cup warm-up games.
The Munster fly-half started Ireland's Six Nations opener in the absence of Jonathan Sexton but has dropped down the pecking order and misses out on the training squad with Sexton, Ian Madigan and Paddy Jackson preferred.
Paul O'Connell will captain the side, but Rhys Ruddock misses out after breaking his arm in the Tbilisi Cup last week.
Ireland head coach Joe Schmidt, commented: "The squad selection has been a long process with some very tight decisions. Some injured players who are getting close to full fitness have been included while others have missed out due to prolonged absence or lack of opportunity to demonstrate their full Test match readiness.
"Rhys Ruddock would have been selected but has been ruled him out after fracturing his arm against Uruguay last week."
Ireland will take on Wales, twice, Scotland and England ahead of the World Cup where they are in a pool with France and Italy.
Ireland Training Squad:
Forwards: Rory Best (Ulster), Michael Bent (Leinster), Jack Conan (Leinster), Sean Cronin (Leinster), Tadhg Furlong (Leinster), Cian Healy (Leinster), Jamie Heaslip (Leinster), Iain Henderson (Ulster), Chris Henry (Ulster), Rob Herring (Ulster), David Kilcoyne (Munster), Jack McGrath (Leinster), Martin Moore (Leinster), Jordi Murphy (Leinster), Sean O'Brien (Leinster), Paul O'Connell (Munster) (c), Tommy O'Donnell (Munster), Peter O'Mahony (Munster), Mike Ross (Leinster), Donnacha Ryan (Munster), Richardt Strauss (Leinster), Devin Toner (Leinster), Dan Tuohy (Ulster)
Backs: Isaac Boss (Leinster), Tommy Bowe (Ulster), Darren Cave (Ulster), Gordon D'Arcy (Leinster), Keith Earls (Munster), Luke Fitzgerald (Leinster), Craig Gilroy (Ulster), Robbie Henshaw (Connacht), Paddy Jackson (Ulster), Felix Jones (Munster), David Kearney (Leinster), Rob Kearney (Leinster), Ian Madigan (Leinster), Kieran Marmion (Connacht), Fergus McFadden (Leinster), Conor Murray (Munster), Jared Payne (Ulster), Eoin Reddan (Leinster), Noel Reid (Leinster), Jonathan Sexton (Racing Metro 92), Andrew Trimble (Ulster), Simon Zebo (Munster)