Joe Schmidt has insisted Jared Payne is too important to Ireland's defence at outside centre to consider the Ulsterman at full-back.
Head coach Schmidt revealed Ireland have not run New Zealand-born utility back Payne at full-back at all in training across the RBS 6 Nations.
Simon Zebo slots in for hamstring injury victim Rob Kearney in the No 15 jersey for Saturday's clash with Italy in Dublin, where Ireland are aiming for their first win in this year's championship at the fourth attempt.
Schmidt claimed he was never tempted to deploy fit-again Payne at full-back and hand Ulster battering ram Stuart McCloskey another opportunity in the centre.
"I don't know what calls there were on the outside for Jared to play full-back," said Schmidt.
"We haven't trained with Jared at 15 so it would be a big step for us to suddenly change that. Rob Kearney trained on Monday and Simon Zebo has played plenty of full-back for us.
"What we lack with Jared Payne not in the midfield has been particularly evident for us, particularly on the edge in defence. We're looking for him to control our defence again in the frontline."
"I've seen a lot of young players really hampered by being thrust into an environment they are not ready for." - Joe Schmidt
Reigning champions Ireland have relinquished their title after two defeats and a draw, building the pressure on boss Schmidt for a victory this weekend.
Ireland have only ever lost once to Italy in Dublin, a 37-29 defeat in 1997, so Saturday's Aviva Stadium clash ought to be the prime chance to experiment and build for the future.
Instead Schmidt has selected his strongest available starting line-up, with Payne's return at outside centre indicative of Ireland's desperation for victory.
The 30-year-old missed Ireland's 21-10 defeat to England at Twickenham with hamstring trouble but has trained without impediment all week.
Ulster powerhouse McCloskey formed a bruising centre pairing with Henshaw against England, but Schmidt has now jumped at the chance to slot Payne back into midfield.
McCloskey drops out of Ireland's matchday squad altogether, the luckless fall guy given Schmidt's reliance on calm customer Payne to bind the backline defence.
Schmidt insisted his selection policy was not "overly conservative", in light of handing McCloskey and young Leinster flanker Josh Van der Flier Test debuts at Twickenham two weeks ago.
"I think we really experimented in the last game," said Schmidt. "To put two guys into their Test match debuts at Twickenham away against a very settled and strong English side, and to have another make his debut off the bench.
"I don't think that's something that's overly conservative, it's giving opportunity and at the same time you're always looking for balance.
"I've been coaching professionally now for 15 years and I've seen a lot of young players really hampered by being thrust into an environment they are not ready for.
"They can lose their confidence and sometimes they don't quite come back in the same way.
"So it's just about getting to know the players and trying to have a balance of opportunity and, at the same time, experience."
Munster wing Keith Earls hailed Payne as the glue in Ireland's backline, insisting the former New Zealand Under-21s star has the knack of helping those around him to shine.
"JP's been brilliant since he's come in," said Earls. "I suppose he took a bit of stick during the World Cup and maybe the last few months, but he's very important to our backline.
"He's a typical Kiwi; really calm, he performs under pressure, makes things look easy and makes players around him look good. And that's great for those of us inside and outside him."
S Zebo; A Trimble, J Payne, R Henshaw, K Earls; J Sexton, C Murray; J McGrath, R Best (capt), M Ross; D Ryan, D Toner; CJ Stander, J van der Flier, J Heaslip.
Replacements: S Cronin, C Healy, N White, U Dillane, R Ruddock, K Marmion, I Madigan, F McFadden.