Following routine wins over Romania and Tonga, Ireland face their defining clash in Rugby World Cup Pool B against reigning champions South Africa in Paris on Saturday.
Fit again hooker Dan Sheehan returns on the bench in a massive boost after a spell on the injury sidelines to replace Rob Herring as cover for fist choice hooker Ronan Kelleher.
In the only change from the win over Tonga, Jamison Gibson-Park returns and is named at out-half to once again partner captain Jonny Sexton replacing Conor Murray.
Bundee Aki is set to win his 50th Test cap as he partners Garry Ringrose in midfield for the third consecutive match. Aki made his debut against South Africa in November 2017.
In the back three Hugo Keenan, Mack Hansen and James Lowe continue, with captain Sexton and the returning Gibson-Park named as half back pair.
The pack is unchanged with Andrew Porter, Ronan Kelleher and Tadhg Furlong in the front row and Tadhg Beirne and James Ryan in the second row.
Peter O’Mahony, Josh van der Flier and Caelan Doris are the loose forward combination.
Dan Sheehan is again a bench option alongside forwards David Kilcoyne, Finlay Bealham, Iain Henderson and Ryan Baird, while Conor Murray, Jack Crowley and Robbie Henshaw cover for the backs.
IRELAND XV vrs SOUTH AFRICA - SATURDAY, 23 SEPTEMBER - Stade de France
15. Hugo Keenan
14. Mack Hansen
13. Garry Ringrose
12. Bundee Aki
11. James Lowe
10. Johnny Sexton
9. Jamison Gibson-Park
1. Andrew Porter
2. Ronan Kelleher
3. Tadhg Furlong
4. Tadhg Beirne
5. James Ryan
6. Peter O’Mahony
7. Josh van der Flier
8. Caelan Doris
Replacements:
16. Dan Sheehan
17. David Kilcoyne
18. Finlay Bealham
19. Iain Henderson
20. Ryan Baird
21. Conor Murray
22. Jack Crowley
23. Robbie Henshaw
