| MD | Players | Club | Nationality | DOB | A(D) |
|---|---|---|---|---|---|
| 08-Feb-2013 |  Jack Dixon | Gwent Dragons | Wales | 13-Dec-1994 | 18(58) |
| 26-Dec-2012 | Hallam Amos | Gwent Dragons | Wales | 24-Sep-1994 | 18(94) |
| 15-Sep-2012 |  Jordan Williams | Scarlets | Wales | 20-Sep-1993 | 18(361) |
| 21-Sep-2012 | Robbie Henshaw | Connacht | Ireland | 12-Jun-1993 | 19(101) |
| 15-Sep-2012 |  Rhys Patchell | Cardiff Blues | Wales | 17-May-1993 | 19(121) |
| 01-Sep-2012 | Harry Robinson | Cardiff Blues | Wales | 16-Apr-1993 | 19(138) |
| 03-Nov-2012 | Angelo Esposito | Benetton Treviso | Italy | 14-Jun-1993 | 19(142) |
| 27-Oct-2012 | Darragh Leader | Connacht | Ireland | 22-May-1993 | 19(158) |
| 31-Aug-2012 |  Chris Farrell | Ulster | Ireland | 16-Mar-1993 | 19(168) |
| 01-Sep-2012 | Thomas Davies | Cardiff Blues | Wales | 10-Mar-1993 | 19(175) |
| 08-Feb-2013 | Ieuan Jones | Gwent Dragons | Wales | 22-Jul-1993 | 19(201) |
| 22-Feb-2013 | Conor Joyce | Ulster | Ireland | 05-Jul-1993 | 19(232) |
| 26-Oct-2012 | David Odiete | Zebre | Italy | 24-Feb-1993 | 19(244) |
| 01-Sep-2012 | Lewis Jones | Cardiff Blues | Wales | 24-Nov-1992 | 19(281) |
| 15-Sep-2012 | Samson Lee | Scarlets | Wales | 30-Nov-1992 | 19(289) |
| 08-Feb-2013 | Stuart Olding | Ulster | Ireland | 11-Mar-1993 | 19(334) |
| 15-Feb-2013 | Mark Bennett | Glasgow Warriors | Scotland | 03-Feb-1993 | 20(12) |
| 02-Nov-2012 | Taylor Paris | Glasgow Warriors | Canada | 06-Oct-1992 | 20(27) |
| 31-Aug-2012 | Jonathan Evans | Gwent Dragons | Wales | 25-Jul-1992 | 20(37) |
| 26-Apr-2013 | Michele Campagnaro | Benetton Treviso | Italy | 13-Mar-1993 | 20(44) |
| 23-Nov-2012 | Peter Nelson | Ulster | Canada | 05-Oct-1992 | 20(49) |
| 03-May-2013 |  Luke McGrath | Leinster | Ireland | 03-Feb-1993 | 20(89) |
| 26-Oct-2012 |  JJ Hanrahan | Munster | Ireland | 27-Jul-1992 | 20(91) |
| 27-Oct-2012 | Stuart Hogg | Glasgow Warriors | Scotland | 24-Jun-1992 | 20(125) |
| 08-Sep-2012 | Matthew Morgan | Ospreys | Wales | 23-Apr-1992 | 20(138) |
| 01-Sep-2012 | George North | Scarlets | Wales | 13-Apr-1992 | 20(141) |
| 28-Sep-2012 |  Harry Leonard | Edinburgh Rugby | Scotland | 28-Apr-1992 | 20(153) |
| 26-Dec-2012 | Aled Davies | Scarlets | Wales | 19-Jul-1992 | 20(160) |
| 31-Aug-2012 | Tom Prydie | Gwent Dragons | Wales | 23-Feb-1992 | 20(190) |
| 05-Oct-2012 | Eli Walker | Ospreys | Wales | 28-Mar-1992 | 20(191) |
| 01-Sep-2012 | Kieran Marmion | Connacht | Ireland | 11-Feb-1992 | 20(203) |
| 28-Sep-2012 | Iain Henderson | Ulster | Ireland | 21-Feb-1992 | 20(220) |
| 31-Aug-2012 | Paddy Jackson | Ulster | Ireland | 05-Jan-1992 | 20(239) |
| 08-Feb-2013 | Giovanni Maistri | Benetton Treviso | Italy | 04-Jun-1992 | 20(249) |
| 01-Sep-2012 | Rhodri Jones | Scarlets | Wales | 23-Dec-1991 | 20(253) |
| 28-Sep-2012 | Leonardo Sarto | Zebre | Italy | 15-Jan-1992 | 20(257) |
| 08-Feb-2013 | Tom Habberfield | Ospreys | Wales | 19-May-1992 | 20(265) |
| 08-Sep-2012 | Sam Parry | Gwent Dragons | Wales | 17-Dec-1991 | 20(266) |
| 03-Nov-2012 | Kirby Myhill | Scarlets | Wales | 05-Feb-1992 | 20(272) |
| 15-Feb-2013 | Thomas Young | Cardiff Blues | Wales | 18-May-1992 | 20(273) |
| 02-Nov-2012 | Luke Hamilton | Cardiff Blues | Scotland | 07-Jan-1992 | 20(300) |
| 30-Nov-2012 | Ross Jones | Ospreys | Wales | 11-Jan-1992 | 20(324) |
| 25-Nov-2012 | Macauley Cook | Cardiff Blues | Wales | 31-Dec-1991 | 20(330) |
| 08-Feb-2013 | Owen Williams | Scarlets | Wales | 27-Feb-1992 | 20(347) |
| 22-Sep-2012 | Lewis Robling | Gwent Dragons | Wales | 05-Oct-1991 | 20(353) |
| 02-Nov-2012 | Greg Hunter | Edinburgh Rugby | Scotland | 26-Sep-1991 | 21(38) |
| 01-Sep-2012 | Andrew Conway | Leinster | Ireland | 11-Jul-1991 | 21(53) |
| 25-Nov-2012 | Owen Williams | Cardiff Blues | Wales | 02-Oct-1991 | 21(55) |
| 15-Sep-2012 | Eoin McKeown | Connacht | Ireland | 23-Jun-1991 | 21(85) |
| 14-Sep-2012 | Tom Grabham | Ospreys | Wales | 20-Jun-1991 | 21(87) |
MD = Match date,
DOB = Date of birth,
A(D) = Age(days).