Ireland and Leinster hooker Sean Cronin is expected to be out for three months because of a shoulder injury.
Cronin, who has 43 caps, has had an operation to repair tendon damage in his left shoulder.
Leinster said the surgery had gone smoothly and the normal recovery period is 12 weeks.
The 28-year-old came off the bench in all of Ireland's games in their recent Six Nations title-winning campaign, providing cover for Rory Best.
He will miss the rest of Leinster's Pro12 campaign, which involves games against Treviso and Edinburgh. The province are out of contention for a semi-final place after losing at Ulster last week.
Ireland's opening World Cup warm-up fixture is against Wales at the Millennium Stadium on 8 August.