Fly-half Haimona had a huge impact when he made his debut for Jacques Brunel's side in the November test series which reaped a win over Samoa before Italy succumbed to a narrow defeat to Argentina and then a heavier loss to South Africa.
The 24-year-old's performances have helped cement what will be his Six Nations debut for his adopted country, with Gori, who has 37 caps for Italy, coming in at scrum half.
Brunel has made only two changes to the side that limited South Africa to a nine-point half-time lead (15-6), when the teams met at the end of the November, before conceding a 22-6 defeat.
The major surprise is in the second row with George Biagi, who has made only three appearances for Italy, replacing Quintin Geldenhuys after he was ruled out for six weeks with knee ligament damage.
In the third row Francesco Minto comes in for Fiji-born Samuela Vunisa, who was called up to Italy's squad along with Haimona in time for the November tests but who is sidelined with injury.
Italy beat Ireland in the Six Nations two years ago, when they also claimed a memorable win over France. But the Azzurri had a disastrous 2014, claiming only one win from 11 games, at home to Samoa.
Last month Brunel had called up 25 of the players he used in the November test series, adding veteran flanker Mauro Bergamasco and 24-year-old wing Giovanbattista Venditti, as well as three debutants.
Zebre centre Giulio Bisegni, Zebre wing Michele Visentin and Calvisano scrum-half Marcello Violi also made the squad.
But of the five, only Venditti has kept his place in the squad for Saturday's match, with second row forward Marco Fuser coming into the squad as cover for Geldenhuys.
With injuries elsewhere, Brunel has turned to youth. But the Frenchman is hoping they seize on the opportunity to lift Italy back to the heady days of 2013.
"We hope to regain the form we had in 2013," Brunel told reporters in Rome on Thursday.
"This first match will give us an idea of how we stand. It won't be the easiest because the Irish are favourites, they're confident, and they won almost everything last year.
"We're hoping they won't be at their very best in their first game of the tournament."
Brunel admitted, meanwhile, he was "a little surprised" by Ireland coach Joe Schmidt's decision to replaced injured fly-half Jonathan Sexton with Ian Keatley.
"We were expecting more (Ian) Madigan," said Brunel. Keatley is "less experienced at international level despite the fact he's a regular with his club team (Munster) and used to playing in the Celtic League.
"They obviously took him because he has the same kind of profile as Sexton."
Veteran lock Paul O'Connell continues to captain Ireland in what will be their first Six Nations since Brian O'Driscoll brought the curtain down on his brilliant career after the team clinched the title in Paris last year.
However, Ireland proved their was life after 'BOD' by winning all three of their recent November Tests, which included victories over South Africa (29-15) and Australia (26-23).
Italy XV for Saturday's Six Nations match at the Stadio Olimpico:
Andrea Masi; Leonardo Sarto, Michele Campagnaro, Luca Morisi, Luke McLean; Kelly Haimona, Edoardo Gori; Francesco Minto, Sergio Parisse (cap), Alessandro Zanni; George Biagi, Josh Furno; Martin Castrogiovanni, Leonardo Ghiraldini, Matias Aguero
Replacements: Andrea Manici, Alberto De Marchi, Dario Chistolini, Marco Fuser, Robert Barbini, Guglielmo Palazzani, Tommaso Allan, Giovanbattista Venditti.