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 Ireland's 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."