Captain Rory Best will miss Ireland’s tour to Australia with a hamstring injury.
Munster's Niall Scannell will replace the British and Irish Lions hooker in the squad, the Irish Rugby Football Union (IRFU) has announced.
Head coach Joe Schmidt told a press conference that vice-captains Johnny Sexton and Peter O'Mahony could share the captaincy for June's three-Test series against the Wallabies.
Ireland confirmed Best’s injury on Twitter, before boss Schmidt explained how his squad may handle the 35-year-old’s absence.
Best has racked up 111 caps since his 2005 Test debut, while Scannell has made just seven international appearances.
The IRFU tweeted: “With RoryBest2 ruled out Joe (Schmidt) has said that JohnnySexton & peterom6 who are Vice Captains may share the captaincy in Australia #TeamOfUs.”
Best sustained his injury in the build-up to Ulster’s Champions Cup play-off with Ospreys, missing the Ravenhill province’s 35-17 win on May 20th.
Now the veteran front-rower has failed to recover in time for Ireland’s tour, leaving Leinster’s Sean Cronin heading the queue to start the first Test, in Brisbane on June 9.
Rob Herring is the other hooker in Ireland’s touring party, with Schmidt now to decide who will skipper the team.
Schmidt’s initial installation of Best as captain for the summer tour had pushed the Ulster star one step closer towards skippering Ireland at the 2019 World Cup.