10 Dec, 12:23
Ireland's John Lacey will referee his first ever RBS 6 Nations match in February, while Alain Rolland is also included in the Elite Panel in what is his last season.
The back-line sees one change with Shane Gahan selected in the centre and Ian McKinley dropping to the bench.
Speaking ahead of the final game of the 2009 Championship, Ireland coach Allen Clarke said: "With Adam Macklin and Shane Gahan coming into the starting line-up, we have focused on improving the accuracy and usage of ball from our set piece.
"The response from the players after a below par performance against Scotland has been excellent and there is a strong determination to finish the Six Nations with a quality performance."
IRELAND UNDER-20 TEAM & REPLACEMENTS (v Wales Under-20s, 2009 RBS U-20 6 Nations Championship, Parc y Scarlets, Llanelli, Friday, March 20, kick-off 7.10pm):
15 - David Kearney (Lansdowne/Leinster)
14 - Ronan O'Mahony (Garryowen/Munster)
13 - Shane Gahan (Lansdowne/Leinster)
12 - Eamonn Sheridan (Lansdowne/Leinster)
11 - Michael Keating (Clontarf/Leinster)
10 - Ian Madigan (Blackrock College/Leinster)
9 - Matthew Healy (Lansdowne/Leinster)
1 - Jack McGrath (St. Mary's College/Leinster)
2 - Thomas Sexton (Old Belvedere/Leinster)
3 - Adam Macklin (Belfast Harlequins/Ulster)
4 - Ciaran Ruddock (Neath/Exiles)
5 - James Sandford (Queens University/Ulster)
6 - Rhys Ruddock (Millfield School/Exiles)
7 - Dominic Ryan (Lansdowne/Leinster)
8 - Peter O'Mahony (Cork Constitution/Munster) (capt)
16 - David McGregor (Ballynahinch/Ulster)
17 - Paddy McAllister (Ballynahinch/Ulster)
18 - Mark Flanagan (UCD/Leinster)
19 - Michael Noone (Seapoint/Leinster)
20 - Conor Murray (Garryowen/Munster)
21 - Andrew Burke (Garryowen/Munster)
22 - Ian McKinley (UCD/Leinster)