Ireland hooker Sean Cronin has been ruled out of the Six Nations after sustaining a hamstring injury.

Cronin suffered the injury while playing for Leinster against Italian side Zebre a fortnight ago and missed the province's Champions Cup match against Montpellier over the weekend. While it was thought the hooker would be fit in time for the latter stages of Ireland's Six Nations campaign, a scan has revealed the severity of Cronin's injury is of such nature that he requires at least 10 weeks of rest.

Leinster assistant coach Stuart Lancaster says it’s quite a significant hamstring injury.

'He’s got himself into great form and now he’ll miss the Six Nations. He went to push off and accelerate around the corner and saw it go. He’s deeply disappointed but he’ll be back a better player,' said Lancaster.

'It’s a real shame for him as he’s actually playing great rugby but it’s a good opportunity for us to get him right and make sure we don’t get a recurrence of this because it must be hugely frustrating for him.'

Cronin's unavailability places his Leinster teammate James Tracy and uncapped duo Niall Scannell and Dave Heffernan in the running for a call-up to the national squad by coach Joe Schmidt. The chosen one will be behind captain Rory Best in the pecking order.

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