Ulster's James McNabney is poised to make his Ireland debut off the bench as head coach Andy Farrell makes seven changes for Saturday's Nations Championship match against Fiji.
In addition to a raft of personnel changes, Farrell has made two key positional switches with Nick Timoney and Mack Hansen moving to number eight and full-back.
Timoney's switch comes amid an injury crisis at number eight, with Caelan Doris, Jack Conan and Sean Jansen all ruled out through injury, while Hansen replaces Hugo Keenan, who drops out of the squad after scoring a hat-trick of tries in the 42-12 win over Argentina.
Jamie Osborne, Bundee Aki, Tommy O'Brien and Jamison Gibson-Park are also drafted into the backline, with Rob Baloucoune and Sam Prendergast retained.
In the pack, Ronan Kelleher starts at hooker with Dan Sheehan ruled out because of concussion, while James Ryan partners stand-in captain Tadhg Beirne in the second row as Joe McCarthy drops out.
With Timoney switching to number eight, former World Rugby player of the year Josh van der Flier is recalled at open-side flanker.
Were McNabney to be called upon, it would cap a remarkable ascent for the 23-year-old, who has started just one game for Ulster this season after recovering from the anterior cruciate ligament injury that forced him to miss the entire 2025-26 campaign.
McNabney is one of four Ulster players on the bench alongside hooker Tom Stewart, prop Tom O'Toole and centre McCloskey, who drops out of the starting line-up for the first time in 2026.
With back-to-back world champions South Africa bringing their much-vaunted scrum power to Dublin next week, Farrell has opted to stick with first-choice props Andrew Porter and Tadhg Furlong.
Behind an experienced second row of Ryan and Beirne, Ryan Baird keeps his place at blind-side flanker after impressing on his return against Argentina, while Timoney is entrusted with a first Test start at number eight after an eye-catching showing at open-side last week.
Back-up lock Darragh Murray is in line to win his fourth cap off the bench.
With Keenan not included, Hansen returns to the full-back jersey. The 28-year-old scored a hat-trick of tries on his first start at 15 against Australia last year.
Tommy O'Brien returns to left wing while Aki - a late withdrawal from the Argentina game because of illness - and Osborne represent a new centre partnership.
Gibson-Park returns at scrum-half after Craig Casey was preferred last week, while Prendergast is retained at fly-half with Ciaran Frawley kept in reserve.
Ireland sit third behind France and England in the Nations Championship northern hemisphere standings with three wins from four games.
Fiji, who have never beaten Ireland, lost 54-17 to France last week and sit bottom of the southern hemisphere table having failed to win a point.
Head coach Jake White has retained only six starters from the defeat in Lyon, with 31-year-old centre Setareki Bituniyata handed a debut.
Ireland: Mack Hansen; Rob Baloucoune, Jamie Osborne, Bundee Aki, Tommy O'Brien; Sam Prendergast, Jamison Gibson-Park; Andrew Porter, Ronan Kelleher, Tadhg Furlong, James Ryan, Tadhg Beirne (capt), Ryan Baird, Josh van der Flier, Nick Timoney.
Replacements: Tom Stewart, Tom O'Toole, Sam Illo, Darragh Murray, James McNabney, Craig Casey, Ciaran Frawley, Stuart McCloskey.
Fiji: Ponipate Loganimasi; Selestino Ravutaumada, Setareki Bituniyata, Josua Tuisova, Jiuta Wainiqolo; Ben Volavola, Frank Lomani; Peni Ravai, Tevita Ikanivere, Luke Tagi, Joseva Tamani, Isoa Nasilasila, Mesake Vocevoce, Lekima Tagitagivalu, Peceli Yato (capt).
Replacements: Zuriel Togiatama, Vilikesa Nairau, Inoke Ravuiwasa, Kitione Salawa, Elia Canakaivata, Terio Tamani, Caleb Muntz, Iosefo Masi.