Ireland star Rob Baloucoune stood down with immediate effect

The Ulster winger had been selected to start in the opening fixture but has been withdrawn as a precaution, handing Jimmy O’Brien an opportunity to come into the starting side. The Leinster utility back will earn his 12th Ireland cap as Andy Farrell's side looks to make a winning start to the new tournament.

O’Brien has become one of Ireland’s most dependable squad players thanks to his versatility, with the ability to cover wing, fullback and centre. Comfortable under the high ball and strong in defence, the 28-year-old has regularly impressed whenever called upon in green and now gets another chance to stake his claim in a highly competitive back three.

While Baloucoune’s absence removes one of Ireland’s most dangerous attacking weapons, O’Brien offers a different skill set, bringing composure, aerial security and a strong kicking game. His experience within Ireland’s systems should ensure there is little disruption despite the late alteration.

The setback will be frustrating for Baloucoune, who had been hoping to cement his place after returning to the international fold. However, with a demanding Nations Championship schedule ahead, Ireland have opted not to take any risks over a muscle injury that could worsen if aggravated.

Ireland will now hope O’Brien can make the most of his opportunity as they begin their campaign against the Wallabies in what promises to be a fiercely contested opening encounter.

15 Hugo Keenan (Leintser)

14. Jimmy O'Brien (Leinster)

13. Garry Ringrose (Leinster)

12. Stuart McCloskey (Ulster)

11. Jamie Osborne (Leinster)

10. Sam Prendergast (Leinster)

9. Jamison Gibson-Park (Leinster)

1. Tom O'Toole (Ulster)

2. Dan Sheehan (capt) (Leinster)

3. Tadhg Furlong (Leinster)

4. Joe McCarthy (Leinster)

5. James Ryan (Leinster)

6. Cian Prendergast (Connaxcht)

7. Josh van der Flier (Leinster)

8. Jack Conan (Leinster)

Replacements: