Huw Anderson moves from wing to full back while Kenzie Jenkins switches to the second row from the back row.
Loosehead prop Morgan Williams comes into the front row with Kian Hire starting at tighthead prop. Cardiff Rugby’s Harry Beddall starts in the back row and also takes over the captaincy from No 8 Morgan Morse.
Walker Price is the only new face in the backline in a side which lost their opening game against England last weekend.
On the replacements bench Saul Hurley comes in for Joe Rees who has had to withdraw through Covid while Dragons’ Gethyn Cannon replaces Lewis Marsh who is undergoing concussion protocols.
O’Brien said he was disappointed with certain areas against England but he added the Welsh side showed what they were capable of in the first 40 minutes of the game so they enter the game against Ireland in a positive frame of mind.
“We’re a young group and we’ve made a few changes going into the Ireland game. They will be another challenge, especially in the contact area.
“It has been great to see the boys together 24 hours a day and we’ve seen a big growth in them on and off the field.”
Wales U18s v Ireland U20s
15 Huw Anderson (Dragons)
14 Walker Price (Dragons)
13 Louie Hennessey (Cardiff Rugby/Hartpury)
12 Harri Ackerman (Dragons)
11 Gabe Lacey (Bristol Bears)
10 Sam Berry (Dragons)
9 Rhodri Lewis (Ospreys);
1 Morgan Williams (Dragons)
2 Isaac Young (Scarlets)
3 Kian Hire (Ospreys)
4 Jonny Green (Halrequins)
5 Kenzie Jenkins (Cardiff Rugby).
6 Lucas de la Rua (Cardiff Rugby)
7 Harry Beddall (Cardiff Rugby, Capt)
8 Morgan Morse (Ospreys)
Replacements:
16 Saul Hurley (Cardiff Rugby)
17 Ioan Emmanuel (Cardiff Rugby)
18 Connal Couch (Dragons)
19 Nick Thomas (Dragons)
20 Gethyn Cannon (Dragons)
21 Orson James (Cardiff Rugby)
22 Harri Wlide (Cardiff Rugby)
23 Cam Davies (Dragons)
24 Ioan Duggan (Dragons)
25 Isaac Morgan (Ospreys)
26 Luca Giannini (Scarlets)
