For the first time in Joe Schmidt's tenure - Ireland will play a game of rugby without one of Rob Kearney, Simon Zebo, or Felix Jones in the 15 jersey. That's 32 games where Schmidt has relied on those three and all of them are unavailable through injury for the first test in South Africa. Jones was forced to retired through injury, and both Kearney and Zebo have been ruled out.
That means we have absolutely no idea who will line up in the backfield for Ireland in Cape Town. There are exactly eight players who have played professional rugby at full-back at some point in their careers, so we assess their chances to be the one selected at the back for Ireland.
NOTE - I've ranked the players in order of how likely I think their chances are - NOT who I'd have at full-back.
1. Robbie Henshaw
Probably the most likely contender. Schmidt seems set at keeping Payne at 13 - and Sexton's injury could actually facilitate moving Henshaw to full-back.
Schmidt will want to make Paddy Jackson as comfortable as possible - so putting Luke Marshall or Stuart Olding at 12, with Payne at 13 to create an Ulster 10-12-13 is the sort of thing that Schmidt dreams of.
Henshaw is too good and too rated to leave out of the side, and might have a chance to show more of his skills in the wider channels.
2. Ian Madigan
Madigan is the only one who has been picked to play fullback by Schmidt back in his Leinster days. He also spent some time there at the end of World Cup warmups.
Schmidt might want to get as many potential 10's on the pitch as possible to 'compensate' for the loss of Johnny Sexton.
3. Keith Earls
Schmidt has shown a willingness to use Earls in a variety of positions, and a return to full-back might be on the cards. He's likely to start somewhere in the first test - be it on the wing or full-back.
You never know.
4. Stuart Olding
Schmidt is a big fan of Stuart Olding. So much so, that his return from injury was enough to relegate Ian Madigan from the squad originally.
He was championing Olding's versatility off the bench in the original squad announcement, and could be the option that Schmidt plucks for.
5. Matt Healy
Everyone remembers Grenoble. It was Matt Healy's second outing from the 15 jersey, and he looked like a natural.
Given Joe's beliefs on winger's workrates, it might be more inclined to take a flier on X-factor at fullback rather than wing. It could be Healy's best chance to play.
6. Tiernan O'Halloran
One of only two players who was consistently played at fullback for their province during the season. O'Halloran tore Kearney a new one in the PRO12 final, and got the belated call-up to replace him in the squad. Will it be a simple case of like for like?
7. Craig Gilroy
See Matt Healy for the reasoning behind X factor. Gilroy actually has more experience at fullback than Healy would, but he's so far down the pecking order in Schmidt's eyes - I'd be surprised if he got any game-time at all.
Gilroy has been known and playing well for Schmidt's entire tenure and he's only played against Georgia in November 2014 under Schmidt.
8. Jared Payne
The one we all want, but the one that will never happen. Payne is the most talented fullback option we have, but Schmidt seems reluctant to move him from 13, despite the fact that he hasn't played anywhere other than fullback since the Six Nations for Ulster.
See Also: Joe Schmidt Calls Up Four Injury Replacements Following Sexton Withdrawal
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