Joey Carbery was great to watch but he has not answered the biggest question about him

"Needs must," said Joe Schmidt.

Ulster desperately need a high-quality outhalf and how they would dearly love to have Joey Carbery up at Ravenhill. But Leinster's needs outweigh the No.10 problems of their northern rivals and the IRFU will leave well enough alone. Saturday evening at the Aviva Stadium proved two things - Carbery is a special talent and Johnny Sexton is one of the very best outhalves in world rugby. Sexton didn't need to play for us to know that but you can see the difference he makes to this Ireland team every time he wears the No.10 jersey. Kieran Marmion and Joey Carbery are very good players. Give them time and further Test match experience and they could go far but they are a level or two below what Conor Murray and Johnny Sexton bring to the table. There is no shame in that, but the narrow win over Fiji only went to prove how much Ireland rely on their first-choice half backs. With Murray and Sexton calling the shots, it gives so much confidence to those around them. Two minor examples, from the Fiji win, were Marmion's box-kicks and Carbery's defence. The Connacht scrum-half is simply not as accurate with his kicks and does not give them as much hang-time, meaning the kick-chasers are at a disadvantage. Carbery, as Joe Schmidt mentioned after the 23-20 win, is brave to a fault. He was up against some big, big Fijians and never shirked a tackle. Still, he is nowhere near as physical as Johnny Sexton and came off second best on a few occasions. He needed the support of Stuart McCloskey and Chris Farrell there [above] but you have to hand it to him for putting it all into slowing 6-foot-5, 21-stone Nemani Nadolo down. Schmidt confirmed, post-match, that Carbery had suffered a suspected fracture to his left arm. He noted that no bones seemed to be displaced so the fracture may be of the hairline variety and may not keep Carbery out longer than six weeks. Further scans will reveal the full extent of the damage. Schmidt was excited when speaking of the 22-year-old's potential at outhalf.

"I thought that ability is coming along, that's one of the biggest responsibilities for a 10. "His vision is just really good too, a cross kick in the first half for Dave Kearney was pin-point perfect and his kick where we thought we scored, the Andrew Conway knock on – was really well placed for us to be competitive at it. "As for his pass to Darren Sweetnam [for his try], I don't think you'd see a much more accurate pass. "Then there's the threat he poses at the line himself. He asked some questions of the Fijians; he's brave, potentially to a fault. He takes no heed of what's in front of him."

The big question about Carbery at outhalf - Can he be relied upon as a goal-kicker - is one that was not answered against Fiji. He missed two conversions, albeit from either touchline, but that was four points Ireland were dearly missing as the Pacific Islanders got right back into the game. Add to that Carbery's two-from-five kicking return in the summer win over the United States and you have an outhalf that has some work to do off the kicking tee. Were Sexton to miss a game in the near future, would Schmidt need a back-up kicking option [such as Rory Scannell] on the field? As recent Six Nations championships have proved, every point counts. Ideally, Carbery would get a run at No.10 when he returns to the Leinster fold. The province will have big PRO14 and Champions Cup fixtures on slate, though, and they have both Sexton and Ross Byrne to call on. "It is what it is," mused Schmidt. "It's an unfortunate situation for us, but I totally understand Leinster's thinking.

"They have Johnny Sexton so he plays, and when Rob Kearney was injured, Joey played full back. I appreciate he gets game time with them. I'd love to see him play 10 more often, I think it'd help his development, but it's a 'need must' situation. "He's such a good young player, though, such a team oriented character, he'd play anywhere. He'll continue to do that if it's for the best of the team."

Ulster and Connacht fans would surely welcome someone of Carbery's ability if he needed a run at 10 but Leinster are not likely to give their gem away. As it stands, Carbery will have to work hard on his kicking technique at every glimpse of a chance he gets. He's getting there but he's not there yet.