Veteran Ireland prop Tadhg Furlong was Sunday ruled out of his team's Six Nations opener against England next weekend because of a calf injury, the IRFU announced.
Leinster forward Furlong, capped 78 times, suffered the injury during a training camp in Portugal and has returned home for further assessment.
The 32-year-old has been replaced in the squad by Jack Aungier of Connacht for Saturday's game in Dublin.
"Tadhg Furlong has been ruled out of the opening week's game after suffering a recurrence of a calf strain in training on Saturday," said an IRFU statement.
Tighthead Furlong has been plagued by injury worries in recent months, missing all four of Ireland's November internationals with a hamstring problem.
He returned for Leinster in their win over La Rochelle in the Champions Cup earlier in January but then missed last weekend's 47-21 win over Bath in the same competition.