| MD | Players | Club | Nationality | DOB | A(D) |
|---|---|---|---|---|---|
| 12-May-2012 |  Stuart Hogg | Glasgow Warriors | Scotland | 24-Jun-1992 | 19(322) |
| 12-May-2012 | Duncan Weir | Glasgow Warriors | Scotland | 10-May-1991 | 21(3) |
| 11-May-2012 | Hanno Dirksen | Ospreys | South Africa | 31-Mar-1991 | 21(42) |
| 12-May-2012 | Robert Harley | Glasgow Warriors | Scotland | 26-May-1990 | 21(352) |
| 12-May-2012 | Alex Dunbar | Glasgow Warriors | Scotland | 23-Apr-1990 | 22(20) |
| 11-May-2012 | Ashley Beck | Ospreys | Wales | 15-Apr-1990 | 22(27) |
| 11-May-2012 |  Simon Zebo | Munster | Ireland | 16-Mar-1990 | 22(57) |
| 11-May-2012 | Daniel Biggar | Ospreys | Wales | 16-Oct-1989 | 22(208) |
| 11-May-2012 | Peter O'Mahony | Munster | Ireland | 17-Sep-1989 | 22(237) |
| 12-May-2012 | Richie Gray | Glasgow Warriors | Scotland | 24-Aug-1989 | 22(262) |
| 11-May-2012 | Justin Tipuric | Ospreys | Wales | 06-Aug-1989 | 22(279) |
| 12-May-2012 | Chris Fusaro | Glasgow Warriors | Scotland | 21-Jul-1989 | 22(296) |
| 12-May-2012 |  David Kearney | Leinster | Ireland | 19-Jun-1989 | 22(328) |
| 11-May-2012 | Conor Murray | Munster | Ireland | 20-Apr-1989 | 23(21) |
| 27-May-2012 | Rhys Webb | Ospreys | Wales | 09-Dec-1988 | 23(169) |
| 12-May-2012 | Eion O'Malley | Leinster | Ireland | 06-Jul-1988 | 23(310) |
| 11-May-2012 | Mike Sherry | Munster | Ireland | 18-Jun-1988 | 23(327) |
| 12-May-2012 | Cian Healy | Leinster | Ireland | 07-Oct-1987 | 24(218) |
| 11-May-2012 | Keith Earls | Munster | Ireland | 02-Oct-1987 | 24(222) |
| 11-May-2012 | Ivan Dineen | Munster | Scotland | 05-Jul-1987 | 24(311) |
| 11-May-2012 | Tommy O'Donnell | Munster | Ireland | 21-May-1987 | 24(356) |
| 12-May-2012 | Pat McArthur | Glasgow Warriors | Scotland | 27-Apr-1987 | 25(16) |
| 11-May-2012 | Ian Keatley | Munster | Ireland | 01-Apr-1987 | 25(41) |
| 12-May-2012 | Sean O'Brien | Leinster | Ireland | 14-Feb-1987 | 25(88) |
| 12-May-2012 | John Barclay | Glasgow Warriors | Scotland | 24-Sep-1986 | 25(231) |
| 12-May-2012 | Devin Toner | Leinster | Ireland | 29-Jun-1986 | 25(318) |
| 12-May-2012 | Fergus McFaddon | Leinster | Ireland | 17-Jun-1986 | 25(330) |
| 12-May-2012 | Daniel Van Der Merwe | Glasgow Warriors | Canada | 28-Apr-1986 | 26(15) |
| 27-May-2012 | Sean Cronin | Leinster | Ireland | 06-May-1986 | 26(22) |
| 12-May-2012 | Richard Strauss | Leinster | Ireland | 29-Jan-1986 | 26(104) |
| 27-May-2012 | Tom Smith | Ospreys | Wales | 14-Dec-1985 | 26(165) |
| 12-May-2012 | Ryan Grant | Glasgow Warriors | Scotland | 08-Oct-1985 | 26(217) |
| 11-May-2012 | Alan Wyn Jones | Ospreys | Wales | 19-Sep-1985 | 26(235) |
| 11-May-2012 | Andrew Bishop | Ospreys | Wales | 07-Aug-1985 | 26(278) |
| 12-May-2012 | Jonathan Sexton | Leinster | Ireland | 11-Jul-1985 | 26(306) |
| 27-May-2012 | Hendrik van der Merwe | Leinster | South Africa | 03-May-1985 | 27(24) |
| 11-May-2012 | Johne Murphy | Munster | Ireland | 10-Nov-1984 | 27(182) |
| 11-May-2012 | Ian Evans | Ospreys | Wales | 04-Oct-1984 | 27(219) |
| 27-May-2012 | Kevin McLaughlin | Leinster | Ireland | 20-Sep-1984 | 27(249) |
| 12-May-2012 | Michael Cusack | Glasgow Warriors | England | 11-Jul-1984 | 27(305) |
| 11-May-2012 | Richard Fussell | Ospreys | Wales | 12-Apr-1984 | 28(29) |
| 12-May-2012 | James Heaslip | Leinster | Ireland | 15-Dec-1983 | 28(149) |
| 11-May-2012 | Richard Hibbard | Ospreys | Wales | 13-Dec-1983 | 28(150) |
| 11-May-2012 | Donnacha Ryan | Munster | Ireland | 11-Dec-1983 | 28(152) |
| 27-May-2012 | Robert Kearney | Leinster | Ireland | 26-Mar-1983 | 29(63) |
| 11-May-2012 | Wian du Preez | Munster | South Africa | 30-Oct-1982 | 29(194) |
| 12-May-2012 | Graeme Morrison | Glasgow Warriors | Scotland | 17-Oct-1982 | 29(208) |
| 11-May-2012 | Lifeimi Mafi | Munster | New Zealand | 15-Aug-1982 | 29(270) |
| 12-May-2012 | Isikeli Nacewa | Leinster | Fiji | 22-Jul-1982 | 29(295) |
| 12-May-2012 | Chris Cusiter | Glasgow Warriors | Scotland | 13-Jun-1982 | 29(334) |
MD = Match date,
DOB = Date of birth,
A(D) = Age(days).