Diack is one of seven uncapped players in the squad, the other newcomers being his Ulster teammate Rob Herring, Cardiff Blues No.8 Robin Copeland, Connacht duo Kieran Marmion and Rodney Ah You, Leinster pair Martin Moore and Jordi Murphy.
A number of players currently injured or returning from injury will remain with their provinces to gain further recovery time or game time.
They include Richardt Strauss, Donnacha Ryan, Roger Wilson, Tommy Bowe, Simon Zebo, Declan Fitzpatrick and Craig Gilroy. Some of these players may yet return for Six Nations matches.
There is also the injured group of Sean O’Brien, Stephen Ferris, Mike Sherry and Stuart Olding who will be unavailable in the longer term.
Ireland head coach Joe Schmidt explained: “As always a number of the selections were very tight. Following on from the November series, there is an experienced core of players in the squad who will offer continuity, as well as some new additions who have been selected with an eye to the future.
“With Robin Copeland returning to play in Ireland next season it will be an opportunity for him to impress during the training week, while some of the younger or less experienced players such as Rob Herring, Iain Henderson, Rhys Ruddock, Kieran Marmion and Felix Jones have turned in some very positive performances to earn spots in the squad.”
Ireland’s opening fixture of the Six Nations is against Scotland at the Aviva Stadium on Sunday, February 2. Reigning champions Wales visit Dublin six days later and Ireland then travel to Twickenham to face England on Saturday, February 22.
Ireland’s final home game of the championship is against Italy on Saturday, March 8 before the team travels to Paris to take on Philippe Saint-Andre’s French side on Saturday, March 15. Ireland’s three home games at the Aviva Stadium are sold out.
The Ireland Wolfhounds will play England Saxons in Kingsholm, Gloucester on Saturday, January 25 with a mixture of youth and experience likely to make up the squad selected for this match.
Extended Ireland Six Nations Squad:
Forwards: Rodney Ah You (Connacht), Stephen Archer (Munster), Rory Best (Ulster), Robin Copeland (Cardiff Blues), Sean Cronin (Leinster), Robbie Diack (Ulster), Cian Healy (Leinster), Jamie Heaslip (Leinster), Iain Henderson, (Ulster), Chris Henry (Ulster), Rob Herring (Ulster), David Kilcoyne (Munster), Mike McCarthy (Leinster), Jack McGrath (Leinster), Martin Moore (Leinster), Jordi Murphy (Leinster), Paul O’Connell (Munster), Tommy O’Donnell (Munster), Peter O’Mahony (Munster), Mike Ross (Leinster), Rhys Ruddock (Leinster), Devin Toner (Leinster), Dan Tuohy (Ulster), Damian Varley (Munster).
Backs: Isaac Boss (Leinster), Darren Cave (Ulster), Gordon D’Arcy (Leinster), Keith Earls (Munster), Luke Fitzgerald (Leinster), Robbie Henshaw (Connacht), Paddy Jackson (Ulster), Felix Jones (Munster), David Kearney (Leinster), Rob Kearney (Leinster), Ian Keatley (Munster), Ian Madigan (Leinster), Kieran Marmion (Connacht), Luke Marshall (Ulster), Fergus McFadden (Leinster), Conor Murray (Munster), Brian O’Driscoll (Leinster), Eoin Reddan (Leinster), Jonathan Sexton (Racing Metro 92), Andrew Trimble (Ulster).
courtesy of Rugby365.com