Murphy has made six changes to his starting XV for the Round 2 fixture, with Patrick Campbell, Sam Prendergast, Michael Moloney, George Hadden, Diarmuid Mangan and George Shaw coming into the side.
Campbell, who was one of the standout performers during Ireland’s Six Nations Grand Slam-winning campaign, has recovered from injury and starts at full-back. His return means Dylan O’Grady switches to the left wing while Aitzol King continues on the right.
The centre pairing of Fionn Gibbons and Daniel Hawkshaw remains unchanged from the Round 1 defeat to France, with Leinster duo Prendergast and Moloney forming a new half-back pairing.
In the pack, Hadden comes into the front row alongside James McCormick and Darragh McSweeney. Mangan steps into the engine room alongside the ever-present Conor O’Tighearnaigh, while James McNabney and captain Reuben Crothers are joined in the back row by number eight Shaw.
Murphy has plenty of options on the bench with teams allowed to name an extended matchday squad of 26 players for the tournament in Italy.
IRELAND U20 Team & Replacements (v South Africa U20, U20 Six Nations Summer Series – Pool A, Payanini Rugby Centre, Wednesday, June 29, kick-off 8pm local time/7pm Irish time):
15\. Patrick Campbell (Young Munster RFC/Munster)
14\. Aitzol King (Clontarf FC/Leinster)
13\. Fionn Gibbons (UCD RFC/Leinster)
12\. Daniel Hawkshaw (Clontarf FC/Leinster)
11\. Dylan O’Grady (UCD RFC/Leinster)
10\. Sam Prendergast (Lansdowne FC/Leinster)
9\. Michael Moloney (UCD RFC/Leinster)
1\. George Hadden (Gorey RFC/Clontarf FC/Leinster)
2. James McCormick (Ballymena RFC/Ulster)
3\. Darragh McSweeney (Shannon RFC/Munster)
4\. Conor O’Tighearnaigh (UCD RFC/Leinster)
5\. Diarmuid Mangan (UCD RFC/Leinster)
6. James McNabney (Ballymena RFC/Ulster)
7. Reuben Crothers (Ballynahinch RFC/Ulster) (capt)
8\. George Shaw (Cardiff University/IQ Rugby)
Replacements:
16. Josh Hanlon (Ballynahinch RFC/Ulster)
17\. Oisin Michel (Lansdowne FC/Leinster)
18\. Kieran Ryan (Shannon RFC/Munster)
19. Adam McNamee (Malone RFC/Ulster)
20. Lorcan McLoughlin (Queen’s University Belfast RFC/Ulster)
21\. Andrew O’Mahony (UCC RFC/Munster)
22. Reece Malone (Loughborough University/Ballynahinch RFC/Ulster)
23\. George Coomber (UCC RFC/Munster)
24\. Shay McCarthy (Young Munster RFC/Munster)
25. Scott Wilson (Queen’s University Belfast RFC/Ulster)
26. Charlie Irvine (Queen’s University Belfast RFC/Ulster).