| MD | Players | Nationality | DOB | A(D) |
|---|---|---|---|---|
| 11-May-2018 | Taufa'ao Filise | Tonga | 26-May-1977 | 40(350) |
| 21-Apr-2018 | Gethin Jenkins | Wales | 17-Nov-1980 | 37(155) |
| 20-Jan-2018 | Matthew Rees | Wales | 09-Dec-1980 | 37(42) |
| 20-Jan-2018 | Damian Welch | Wales | 28-Jul-1982 | 35(177) |
| 11-May-2018 | Nick Williams | New Zealand | 02-Dec-1983 | 34(161) |
| 11-May-2018 | Josh Turnbull | Wales | 12-Mar-1984 | 34(60) |
| 11-May-2018 | Reynold Lee-lo | Samoa | 28-Feb-1986 | 32(72) |
| 11-May-2018 | Rhys Gill | Wales | 30-Oct-1986 | 31(194) |
| 31-Mar-2018 | George Earle | South Africa | 09-Jan-1987 | 31(81) |
| 21-Apr-2018 | Anton Peikrishvili | Georgia | 18-Sep-1987 | 30(216) |
| 09-Dec-2017 | James Down | Wales | 29-Aug-1987 | 30(103) |
| 11-May-2018 | Blaine Scully | United States | 29-Feb-1988 | 30(72) |
| 11-May-2018 | Kristian Dacey | Wales | 25-Jul-1989 | 28(290) |
| 20-Jan-2018 | Lloyd Williams | Wales | 30-Nov-1989 | 28(51) |
| 21-Apr-2018 | Alex Cuthbert | Wales | 05-Apr-1990 | 28(16) |
| 11-May-2018 | Willis Halaholo | Wales | 06-Jul-1990 | 27(309) |
| 11-May-2018 | Josh Navidi | Wales | 30-Dec-1990 | 27(132) |
| 11-May-2018 | Gareth Anscombe | Wales | 10-May-1991 | 27(1) |
| 13-Oct-2017 | Oliver Robinson | England | 21-Jul-1991 | 26(85) |
| 20-Jan-2018 | Macauley Cook | Wales | 31-Dec-1991 | 26(21) |
| 17-Dec-2017 | Matthew Morgan | Wales | 23-Apr-1992 | 25(238) |
| 11-May-2018 | Ellis Jenkins | Wales | 29-Apr-1993 | 25(12) |
| 17-Dec-2017 | Bradley Thyer | Wales | 07-Feb-1993 | 24(313) |
| 11-May-2018 | Tomos Williams | Wales | 01-Jan-1995 | 23(130) |
| 17-Dec-2017 | Aled Summerhill | Wales | 02-Nov-1994 | 23(45) |
| 20-Jan-2018 | Garyn Smith | Wales | 12-Jul-1995 | 22(193) |
| 31-Mar-2018 | Dillon Lewis | Wales | 04-Jan-1996 | 22(87) |
| 11-May-2018 | Seb Davies | Wales | 15-May-1996 | 21(361) |
| 11-May-2018 | Jarrod Evans | Wales | 25-Jul-1996 | 21(290) |
| 20-Oct-2017 | Corey Domachowski | Wales | 19-Sep-1996 | 21(31) |
| 11-May-2018 | Owen Lane | Wales | 20-Dec-1997 | 20(142) |
MD = Match date,
DOB = Date of birth,
A(D) = Age(days).