Sam Prendergast will start at fly-half for reigning champions Ireland when they begin their Six Nations title defence against England in Dublin on Saturday.
Prendergast, 21, has been selected for his Six Nations debut ahead of Jack Crowley, a mainstay of last year's title-winning team but now on the bench.
Interim Ireland coach Simon Easterby, in charge while Andy Farrell is seconded to the British and Irish Lions for the 2025 tour of Australia, has also recalled Ryan Baird to the back row, with Garry Ringrose preferred to Leinster teammate Robbie Henshaw at outside centre.
Baird's inclusion means Tadhg Beirne switches to the second row, with Joe McCarthy ruled out through injury.
Prendergast was seen with a heavily strapped leg in training earlier this week but Ireland attack coach Andrew Goodman played down any injury concerns on Tuesday.
He will partner experienced scrum-half Jamison Gibson-Park behind a pack featuring Ireland captain Caelan Doris at No 8.
Prendergast was preferred as a starter to Crowley for Ireland's most recent test, a 22-19 win over Australia in late November.
But Saturday's match will be the most high-profile game of his career, with Ireland looking to avenge a narrow loss to England at Twickenham last year that denied them a Grand Slam.
"We've enjoyed some competitive (training) sessions and it wasn't easy selecting a squad for this week's game given the quality of those who haven't made the final 23," said Easterby after announcing his team on Thursday.
"England are a talented squad with quality across their panel and we know that we will need to hit the ground running to deliver a winning performance."
Ringrose's inclusion is the only change to Ireland's backline from the Australia game, with Hugo Keenan at full-back and Mack Hansen on the right wing.
James Lowe, who returned from injury in Leinster's win over the Stormers last week, is on the left wing.
Up front, Ronan Kelleher remains at hooker, with Dan Sheehan, back after six months out with a knee injury, on the bench.
Finlay Bealham stays at tighthead prop in the ongoing absence of the sidelined Tadhg Furlong.
IRELAND (15-1)
Hugo Keenan; Mack Hansen, Garry Ringrose, Bundee Aki, James Lowe; Sam Prendergast, Jamison Gibson-Park; Caelan Doris (capt), Josh van der Flier, Ryan Baird; Tadhg Beirne, James Ryan; Finlay Bealham, Ronan Kelleher, Andrew Porter
REPLACEMENTS: Dan Sheehan, Cian Healy, Thomas Clarkson, Iain Henderson, Jack Conan, Conor Murray, Jack Crowley, Robbie Henshaw