Harry Byrne will compete with Sam Prendergast and Jack Crowley for Ireland's fly-half duties after being included in Andy Farrell's squad for the Six Nations.
Byrne comes into contention for the opener against France in Paris on 5 February after being included in a 37-man group alongside his rival playmakers, as well as utility back Ciaran Frawley.
The 26-year-old won the last of his four caps in 2024 but has been in impressive form for Leinster since the autumn and is set to challenge the established order in the number 10 jersey.
Munster second row Edwin Edogbo and Ulster scrum-half Nathan Doak are the only uncapped players among the 37, who are led by No 8 Caelan Doris.
Ireland have been been beset by injury with Andrew Porter and Robbie Henshaw missing the start of the competition because of respective calf and knee issues.
Cormac Izuchukwu, Calvin Nash, Jimmy O'Brien, Ryan Baird, Shayne Bolton, Mack Hansen, Jordan Larmour and Paddy McCarthy are also in the treatment room.
Hugo Keenan is present despite not having played this season because of hip surgery that was completed after the British and Irish Lions tour to Australia.
"I'm getting there," Keenan said. "I feel I've turned the corner in the last couple of weeks.
"I've been back out training fully with Leinster the last week or two, so starting to come good."
Ireland lost their Six Nations crown to France last year and face a tough 2026 campaign with away trips to Paris and London.
"I believe we have a talented and committed group who have the aptitude and drive to bring success to Ireland over the coming weeks," Farrell said.
"The squad has evolved over the last 18 months with 12 players making their international debuts over the last year alone and I know how keen this group is to make its mark for Ireland.
"Led once more by Caelan, we know that we have to hit the ground running and we're looking forward to regrouping on Sunday and meeting the challenges ahead in a positive frame of mind.
"The Six Nations is an incredible tournament which brings out the best in players and I have no doubt that these fixtures will be keenly contested once more.
"The competition levels across all of the opposing teams has never been higher and we have an exciting challenge first up away to France in Paris to kick things off. It will be a huge test as always."
PA
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