Uncapped Munster players Felix Jones and Conor Murray have been named in a 43-man squad for Ireland's first pre-season camp ahead of the Guinness Summer Series and the Rugby World Cup.
The squad includes several players who are in the process of returning from long-term injuries, including Stephen Ferris and Rob Kearney.
Short-term injury victims Shane Jennings and Tony Buckley are also named in the panel.
Shane Horgan is out with a knee injury.
Horgan and Ulster duo Ian Humphreys and Nevin Spence were not considered for selection after undergoing surgery on long-standing injuries.
All three have been ruled out of the Rugby World Cup conditioning schedule which would enable them to build up the required fitness levels, so they will not be involved in the series of summer matches ahead of the World Cup.
It would therefore seem unlikely that Horgan, who has won 65 caps, will play any part in the World Cup itself.
Full-back Jones and scrum-half Murray were both impressive for Munster last season.
Connacht pair Mike McCarthy and Brett Wilkinson are the only other uncapped players in the squad.
The selected players will gather at Kildare for the first of three scheduled camps during June and July.
"This is the first step in preparation for the Rugby World Cup and the group called into our first camp shows that there is competition for places right across the board," said Ireland coach Declan Kidney, whose has left the door open for others who have not been included at this stage.
"There are players who we have identified as part of the larger Rugby World Cup squad who will not be in the first camp and will be based with their provincial and club fitness staff, but that may change as we go through June and July, so none of that larger group are necessarily out of contention for the final squad," he added.
Ireland squad: Backs: I Boss (Leinster), T Bowe (Ospreys), G D'Arcy (Leinster), G Duffy (Connacht), K Earls (Munster), L Fitzgerald (Leinster), F Jones (Munster), R Kearney (Leinster), F McFadden (Leinster), G Murphy (Leicester), C Murray (Munster), B O'Driscoll (Leinster), R O'Gara (Munster), T O'Leary (Munster), E Reddan (Leinster), J Sexton (Leinster), P Stringer (Munster), A Trimble (Ulster), P Wallace (Ulster).
Forwards: R Best (Ulster), T Buckley (Sale Sharks), T Court (Ulster), S Cronin (Leinster), L Cullen (Leinster), S Ferris (Ulster), J Flannery (Munster), J Hayes (Munster), C Healy (Leinster), J Heaslip (Leinster), M Horan (Munster), S Jennings (Leinster), D Leamy (Munster), M McCarthy (Connacht), K McLaughlin (Leinster), S O'Brien (Leinster), D O'Callaghan (Munster), P O'Connell (Munster), M O'Driscoll (Munster), M Ross (Leinster), D Ryan (Munster), D Varley (Munster), D Wallace (Munster), B Wilkinson (Connacht).