Sean Cronin looks likely to miss the entirety of Ireland's Six Nations campaign with a hamstring injury after Leinster confirmed that he will be out of action for up to 10 weeks.
Cronin went off injured in his side's comprehensive 70-6 Pro12 victory over Zebre on 6 January and it was thought that he had only suffered a hamstring strain.
However a scan has shown that the injury is much worse than initially feared and confirmed that he has suffered a high-grade hamstring tear, ruling him out of action for up to ten weeks.
Cronin's injury leaves Ireland looking very light in cover for Rory Best as hooker.
Leinster's James Tracy, whose has been ahead of Richardt Strauss at the province, played in the November International against Canada, while Niall Scannell of Munster might now come into the selection equation.
Elsewhere, a decision on the availability of Robbie Henshaw, flanker Seán O'Brien and captain Isa Nacewa for the final game in the pool stages will be made later this week.
O'Brien missed the rout of Montpellier last week with a tightness in his calf, while centre Henshaw was withdrawn during the encounter at the RDS with a thigh strain.
Nacewa suffered a dead leg against the French side, and he too will be assessed later in the week.
Rob Kearney came through his return to action last week unscathed, while prop Mike Ross continues his rehabilitation and is expected to return to light training this week.
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