Jack Carty will replace Johnny Sexton at fly-half in one of four changes made by Ireland coach Joe Schmidt for the encounter with Rugby World Cup hosts Japan.
Reigning World Rugby Player of the Year Sexton came off in Ireland's first game of the tournament – a 27-3 victory over Scotland – having received treatment on a thigh injury in the first half.
Schmidt described the change as Ireland just "being super cautious", but Carty will feature at 10 against Japan in their second Pool A clash.
Full-back Rob Kearney, wing Keith Earls and centre Chris Farrell will also come into the XV in place of Jordan Larmour, Andrew Conway and Bundee Aki.
Centre Aki is not in the squad, despite being passed fit after failing a head injury assessment in the Scotland game, while Peter O'Mahony will play having gone through the same protocol.
Joey Carbery is back on the bench following an ankle injury, but centre Robbie Henshaw again misses out on the matchday squad with a hamstring problem.
Ireland team to face Japan: Rob Kearney; Keith Earls, Garry Ringrose, Chris Farrell, Jacob Stockdale, Jack Carty, Conor Murray; Cian Healy, Rory Best, Tadhg Furlong, Iain Henderson, James Ryan, Peter O'Mahony, Josh van der Flier, CJ Stander.
Replacements: Sean Cronin, David Kilcoyne, Andrew Porter, Tadhg Beirne, Rhys Ruddock, Luke McGrath, Joey Carbery, Jordan Larmour.