Ireland fly-half Sam Prendergast will start his first Six Nations game in Saturday's opener against England and marshal a near full-strength side as the holders bid to win a third successive title for the first time.
Lock Joe McCarthy, who has started Ireland's 11 previous games, joined prop Tadhg Furlong on the short injury list after sustaining a head injury in training on Wednesday.
His absence paves the way for Ryan Baird to come into the back-row to start just his seventh test, with Tadhg Beirne moving to second row.
Leinster's Baird has won the majority of his 24 caps off the bench and played a part in each of Ireland's Six Nations games last season.
Prendergast, 21, has impressed greatly for club and country since making his Ireland debut in November and edges out Munster fly-half Jack Crowley, who helped guide the Irish to the title last year in his breakthrough campaign.
When asked about the decision to pick Prendergast ahead of Crowley, Easterby told reporters: "They are going to play a lot of rugby and compete for a long time, I think. This decision has gone Sam's way.
"We felt like he [Prendergast] did really well in November, he got a taste for international rugby. He went away and played really well for Leinster in a good period for them, but he was a big part of the successes across the December window and into the new year.
"Jack played really well in Northampton in the week prior to camp and he also comes in with a lot of credit in the bank, in terms of what he's done in the last 18 months, two years.
"Also in the back end of that Australia game, he came on and finished the game really strongly and saw out the game so yeah, one of the tough calls but there was probably six or seven of those decisions throughout the team selection that we would have been happy to go either way with players."
Finlay Bealham comes in as an increasingly trusted back-up for the often-injured Furlong and will pack down alongside Andrew Porter and hooker Ronan Kelleher.
First-choice hooker Dan Sheehan is also back among a bench loaded with firepower and experience after being named man of the match and scoring two tries for Leinster in his comeback from an ACL injury on Saturday.
There was no place in the matchday squad for Peter O'Mahony, who captained Ireland to success last year, with the fit again Jack Conan preferred on the bench.
Ireland:
Andrew Porter, Rónan Kelleher, Finlay Bealham, James Ryan, Tadhg Beirne, Ryan Baird, Josh van der Flier, Caelan Doris (captain), Jamison Gibson-Park, Sam Prendergast, James Lowe, Bundee Aki, Garry Ringrose, Mack Hansen, Hugo Keenan.
Replacements: Dan Sheehan, Cian Healy, Thomas Clarkson, Iain Henderson, Jack Conan, Conor Murray, Jack Crowley, Robbie Henshaw.
Relive three classic Six Nations games between Ireland and England ahead of the 2025 tournament this weekend.
Further reading:
- Why each team will find Six Nations success, and why they won't
- WATCH: Can Scotland win their first title since 1999? ESPN writers debate
- Six Nations and Women's Six Nations: Full fixture list
- Six Nations history, past winners, more