| MD | Players | Nationality | DOB | A(D) |
|---|---|---|---|---|
| 15-Oct-2017 | Keelan Giles | Wales | 29-Jan-1998 | 19(259) |
| 15-Oct-2017 | Owen Watkin | Wales | 12-Oct-1996 | 21(3) |
| 21-Oct-2017 | Adam Beard | Wales | 07-Jan-1996 | 21(288) |
| 15-Oct-2017 | Scott Otten | Wales | 19-Jul-1994 | 23(88) |
| 15-Oct-2017 | Nicky Smith | Wales | 07-Apr-1994 | 23(191) |
| 09-Dec-2017 | Oliver Cracknell | Wales | 26-May-1994 | 23(197) |
| 09-Dec-2017 | Sam Davies | Wales | 06-Oct-1993 | 24(64) |
| 15-Oct-2017 | Cory Allen | Wales | 11-Feb-1993 | 24(246) |
| 21-Oct-2017 | Sam Cross | Wales | 26-Aug-1992 | 25(56) |
| 15-Oct-2017 | Dan Baker | Wales | 05-Jul-1992 | 25(102) |
| 21-Oct-2017 | Tom Habberfield | Wales | 19-May-1992 | 25(155) |
| 21-Oct-2017 | Sam Parry | Wales | 17-Dec-1991 | 25(309) |
| 21-Oct-2017 | Jeff Hassler | Canada | 21-Aug-1991 | 26(62) |
| 09-Dec-2017 | Hanno Dirksen | South Africa | 31-Mar-1991 | 26(254) |
| 17-Dec-2017 | Ben John | Wales | 28-Feb-1991 | 26(293) |
| 21-Oct-2017 | James King | Wales | 24-Jul-1990 | 27(89) |
| 13-Jan-2018 | Ashley Beck | Wales | 15-Apr-1990 | 27(273) |
| 21-Oct-2017 | Guy Mercer | England | 12-Dec-1989 | 27(313) |
| 15-Oct-2017 | Daniel Biggar | Wales | 16-Oct-1989 | 27(364) |
| 15-Oct-2017 | Justin Tipuric | Wales | 06-Aug-1989 | 28(70) |
| 15-Oct-2017 | Rhys Webb | Wales | 09-Dec-1988 | 28(310) |
| 15-Oct-2017 | Daniel Evans | Wales | 15-Nov-1988 | 28(334) |
| 15-Oct-2017 | Dimitri Arhip | Moldova | 12-Nov-1988 | 28(337) |
| 09-Dec-2017 | Scott Baldwin | Wales | 12-Jul-1988 | 29(150) |
| 15-Oct-2017 | Kieron Fonotia | Samoa | 02-Feb-1988 | 29(256) |
| 15-Oct-2017 | Dan Lydiatt | Wales | 18-Dec-1987 | 29(302) |
| 15-Oct-2017 | Alan Wyn Jones | Wales | 19-Sep-1985 | 32(26) |
| 13-Jan-2018 | Robert McCusker | Wales | 12-Oct-1985 | 32(93) |
| 15-Oct-2017 | Bradley Davies | Wales | 09-Jan-1985 | 32(279) |
MD = Match date,
DOB = Date of birth,
A(D) = Age(days).