Jacob Stockdale was a notable absentee from Ireland’s Six Nations squad, which included uncapped duo Craig Casey and Tom O’Toole.
Head coach Andy Farrell said Ulster back Stockdale would “not be available to us” as he named a 36-man selection for the tournament.
The 24-year-old suffered a knee injury during his province’s PRO14 win over Munster on January 2.
Fly-half Johnny Sexton will captain his country for a second successive Championship campaign, while Iain Henderson, Tadhg Furlong, Peter O’Mahony and James Lowe were all selected, despite injury concerns.
There was also a recall for Leinster back row Rhys Ruddock, who won the last of his 26 international Test caps during the 2019 World Cup quarter-final defeat to New Zealand.
Munster scrum-half Casey, a Grand Slam winner with Ireland Under-20s in 2019, received his first senior call-up, while Ulster prop O’Toole was named in his country’s squad at the start of the 2020 Championship but did not feature.
Ireland begin the tournament away to Wales on Sunday, February 7.
Experienced prop Furlong has not played for almost a year due to back, calf and hamstring problems, while Ulster captain Henderson has been sidelined since suffering knee ligament damage in the Autumn Nations Cup win over Scotland early last month.
New Zealand-born wing Lowe, who made his Ireland debut in November, has recently returned to training with Leinster following a groin problem and flanker O’Mahony appears to be showing no lasting effects following neck and leg issues suffered playing for Munster at the weekend.
Connacht duo Jack Carty and Kieran Marmion, Leinster scrum-half Luke McGrath, and Ulster number nine John Cooney are among the players to be overlooked.
Coach Farrell told the IRFU website: “Since the Autumn international window the club season has had a good few disruptions and the cancellation of the European fixtures means there have been less opportunities for players to show form or to return from injury and get some minutes under their belts.
“Tadhg (Furlong) hasn’t played in quite a while but he is ready to join the group.
“Unfortunately, Jacob (Stockdale) will not be available to us.”
After travelling to Cardiff, Ireland host France a week later before a trip to Rome to take on Italy on February 27.
Farrell’s men face Scotland at Murrayfield on March 14 before completing the tournament with the visit of reigning champions England six days later.
— Irish Rugby (@IrishRugby) January 25, 2021
Ireland Six Nations Squad
Forwards: Tadhg Beirne (Munster), Will Connors (Leinster), Caelan Doris (Leinster), Ultan Dillane (Connacht), Tadhg Furlong (Leinster), Cian Healy (Leinster), Dave Heffernan (Connacht), Iain Henderson (Ulster), Rob Herring (Ulster), Ronan Kelleher (Leinster), Dave Kilcoyne (Munster), Peter O’Mahony (Munster), Tom O’Toole (Ulster)*, Andrew Porter (Leinster), Quinn Roux (Connacht), Rhys Ruddock (Leinster), James Ryan (Leinster), CJ Stander (Munster), Josh van der Flier (Leinster)
Backs: Bundee Aki (Connacht), Billy Burns (Ulster), Ross Byrne (Leinster), Craig Casey (Munster)*, Andrew Conway (Munster), Shane Daly (Munster), Keith Earls (Munster), Chris Farrell (Munster), Jamison Gibson-Park (Leinster), Robbie Henshaw (Leinster), Hugo Keenan (Leinster), Jordan Larmour (Leinster), James Lowe (Leinster), Stuart McCloskey (Ulster), Conor Murray (Munster), Garry Ringrose (Leinster), Jonathan Sexton (CAPTAIN, Leinster)
*Denotes uncapped player