Joe Schmidt has admitted he cannot "ask too much more" of Robbie Henshaw as the Connacht centre wrestles with Brian O'Driscoll's legacy.
Henshaw will have his first tangible crack at Ireland's vacant 13 shirt against Australia on Saturday when he lines up alongside Gordon D'Arcy in Ireland's midfield.
Head coach Schmidt expects Henshaw to form a solid partnership with Leinster stalwart D'Arcy, with Jared Payne ruled out through foot trouble.
Payne's injury means the wait to anoint now-retired O'Driscoll's great successor will run until the RBS 6 Nations, but Schmidt is demanding solidity first against the Wallabies.
"I don't know if you can ask too much more of Robbie," said Schmidt. " I thought he delivered a really solid performance against South Africa. It was very seamless, him moving into 12.
"At 13 there will be some different challenges: Israel Folau will be coming into that area, there will be some traffic for Johnny (Jonathan Sexton), Gordon and Robbie to cope with.
"Robbie must also link with the wingers and that will be another challenge for him.
"Robbie and Gordon spent a bit of time together when D'Arcy got back fully fit. They've had a little bit of time together, they've enjoyed two training sessions together this week, that's pretty much all we've had time to do.
"I'm just hoping they can feed off each other, connect and link really well, and make sure there's no space for some of those big Australian runners to come through.
"If they do that really well they'll have had a pretty good day at the office."
Schmidt has brought back all his big guns for the visit of Australia, following last weekend's routine 49-7 victory over Georgia.
Mike Ross and Simon Zebo are the only two survivors from that six-try rout, with fit-again Rory Best back at hooker.
Rhys Ruddock returns at openside flanker given Chris Henry's ongoing recovery from his brain injury.
Henshaw thrived at inside centre in Ireland's 29-15 South Africa victory, but will revert to his more accustomed 13 role this weekend.
Fly-half Johnny Sexton is aiming "not to get too bogged down" by facing his Leinster mentor Michael Cheika, the new Australia boss.
Sexton hailed Cheika as "instrumental" in the rise of Leinster and Ireland, carried on by Schmidt at first provincial and now national level.
"Cheiks will change things a lot, he knows we'll have done a lot of analysis, so I'm sure he'll throw a different picture at us on Saturday," said Sexton.
"He'll probably know us as players and characters, and he'll try to tap into that.
"We're trying not to get too bogged down with the Michael Cheika factor. We've got great respect for what he did for Leinster Rugby and for Irish rugby.
"We're all still in touch with him, I texted him a couple of weeks ago to congratulate him on the new job, and he texted back looking for a few tips on the Welsh boys.
"So we still keep in touch but we haven't been in touch this week, but we'll have a catch-up on Saturday after the game.
"I just think in terms of the set-up at Leinster, he was instrumental in changing our mindset, changing the culture in the organisation. And that allowed Joe to come in and take off, take the organisation on the way he did, b ut without Cheiks that wouldn't have been as seamless as it was."