| MD | Players | Club | Nationality | DOB | A(D) |
|---|---|---|---|---|---|
| 02-Nov-2020 |  Joe Hawkins | Ospreys | Wales | 11-Jun-2002 | 18(145) |
| 24-Oct-2020 | Jamie Dobie | Glasgow Warriors | Scotland | 07-Jun-2001 | 19(139) |
| 02-Oct-2020 | Federico Mori | Zebre | Italy | 13-Oct-2000 | 19(354) |
| 29-Nov-2020 |  Gwilym Bradley | Cardiff Blues | Wales | 10-Sep-2000 | 20(80) |
| 08-Nov-2020 |  Jac Price | Scarlets | Wales | 04-Aug-2000 | 20(96) |
| 16-Nov-2020 |  Ethan McIlroy | Ulster | Ireland | 10-Aug-2000 | 20(98) |
| 02-Oct-2020 | Paolo Garbisi | Benetton Treviso | Italy | 03-Jun-2000 | 20(121) |
| 02-Nov-2020 | Josh Thomas | Ospreys | Wales | 30-Jun-2000 | 20(125) |
| 23-Oct-2020 | Filippo Alongi | Benetton Treviso | Italy | 27-Apr-2000 | 20(179) |
| 16-Nov-2020 | Manuel Zuliani | Benetton Treviso | Italy | 26-Apr-2000 | 20(204) |
| 09-Nov-2020 |  Nathan Chamberlain | Edinburgh Rugby | Scotland | 14-Mar-2000 | 20(240) |
| 25-Oct-2020 | Jack Blain | Edinburgh Rugby | Scotland | 21-Feb-2000 | 20(247) |
| 23-Oct-2020 | Jac Morgan | Scarlets | Wales | 21-Jan-2000 | 20(276) |
| 08-Nov-2020 |  Michael Milne | Leinster | Ireland | 05-Feb-2000 | 20(277) |
| 09-Oct-2020 | Taine Basham | Gwent Dragons | Wales | 02-Nov-1999 | 20(342) |
| 15-Nov-2020 | Tiaan Thomas-Wheeler | Ospreys | Wales | 19-Nov-1999 | 20(362) |
| 23-Oct-2020 | Scott Penny | Leinster | Ireland | 22-Sep-1999 | 21(32) |
| 02-Oct-2020 | Stewart Moore | Ulster | Ireland | 08-Aug-1999 | 21(56) |
| 14-Nov-2020 | Colm Reilly | Connacht | Ireland | 08-Sep-1999 | 21(68) |
| 10-Oct-2020 | Ryan Baird | Leinster | Ireland | 26-Jul-1999 | 21(77) |
| 23-Oct-2020 | Liam Turner | Leinster | Ireland | 22-Jul-1999 | 21(94) |
| 01-Nov-2020 |  Josh Wycherley | Munster | Ireland | 22-Jul-1999 | 21(103) |
| 10-Oct-2020 | Ben Healy | Munster | Ireland | 29-Jun-1999 | 21(104) |
| 08-Nov-2020 | Cai Evans | Ospreys | Wales | 23-Jun-1999 | 21(139) |
| 29-Nov-2020 | Romain Favaretto | Benetton Treviso | France | 11-Jul-1999 | 21(142) |
| 16-Nov-2020 | Jamie Hill | Cardiff Blues | Wales | 14-Jun-1999 | 21(156) |
| 24-Oct-2020 | Dewi Lake | Ospreys | Wales | 16-May-1999 | 21(162) |
| 01-Nov-2020 | Morgan Jones | Scarlets | Wales | 23-May-1999 | 21(163) |
| 03-Oct-2020 | Craig Casey | Munster | Ireland | 19-Apr-1999 | 21(168) |
| 23-Oct-2020 | Harry Byrne | Leinster | Ireland | 22-Apr-1999 | 21(185) |
| 01-Nov-2020 | Keynan Knox | Munster | South Africa | 06-Apr-1999 | 21(210) |
| 08-Nov-2020 | Ryan Conbeer | Scarlets | Wales | 05-Feb-1999 | 21(277) |
| 26-Oct-2020 | John Hodnett | Munster | England | 10-Jan-1999 | 21(290) |
| 03-Oct-2020 | Tom Rogers | Scarlets | Wales | 17-Dec-1998 | 21(291) |
| 08-Nov-2020 | Antoine Kouassi Koffi | Zebre | Italy | 15-Jan-1999 | 21(298) |
| 09-Nov-2020 | Max Llewellyn | Cardiff Blues | Wales | 13-Jan-1999 | 21(301) |
| 08-Nov-2020 | Will Griffiths | Ospreys | Wales | 25-Dec-1998 | 21(319) |
| 25-Oct-2020 | Jack Aungier | Connacht | Ireland | 20-Nov-1998 | 21(340) |
| 23-Oct-2020 | Nicola Casilio | Zebre | Italy | 12-Oct-1998 | 22(12) |
| 22-Nov-2020 | Rhys Josh Davies | Ospreys | Wales | 09-Nov-1998 | 22(14) |
| 02-Oct-2020 | James Hume | Ulster | Ireland | 07-Sep-1998 | 22(26) |
| 23-Oct-2020 | Dan Sheehan | Leinster | Ireland | 17-Sep-1998 | 22(37) |
| 03-Oct-2020 | Morgan Morris | Ospreys | Wales | 28-Aug-1998 | 22(37) |
| 01-Nov-2020 | Ben Fry | Gwent Dragons | Wales | 26-Sep-1998 | 22(37) |
| 02-Oct-2020 | Michael Lowry | Ulster | Ireland | 20-Aug-1998 | 22(44) |
| 23-Nov-2020 | Jack O'Sullivan | Munster | Ireland | 01-Oct-1998 | 22(54) |
| 23-Oct-2020 | Michalangelo Biondelli | Zebre | Italy | 15-Aug-1998 | 22(70) |
| 02-Nov-2020 | Giovanni D'Onofrio | Zebre | Italy | 25-Aug-1998 | 22(70) |
| 03-Oct-2020 | Matt Fagerson | Glasgow Warriors | Scotland | 16-Jul-1998 | 22(80) |
| 29-Nov-2020 | Matteo Canali | Benetton Treviso | Italy | 11-Sep-1998 | 22(80) |
MD = Match date,
DOB = Date of birth,
A(D) = Age(days).