Leinster's Sean O'Brien likely to miss start of Six Nations with injury

Sean O'Brien's injury nightmare looks set to continue with Leinster saying the back-row is likely to be out for eight to 12 weeks.

O'Brien made a long-awaited return to the Ireland team against Argentina nine days ago - his first Ireland start in almost a year - but was forced off before half-time with a broken arm.

Leinster head coach Leo Cullen issued a squad update today and confirmed that O'Brien underwent a surgical procedure on the injury.

With Ireland's Six Nations campaign kicking off on February 2, O'Brien is likely to miss out for the start of their title defence.

Cullen also gave an update Dan Leavy, who was withdrawn from the Ireland squad to play New Zealand a day after being named to start.

Leinster say Leavy "sustained a strain to his neck and is undergoing a period of rehabilitation".

He will not be available for Leinster's Pro14 clash with Ospreys on Friday.

Robbie Henshaw, who missed out on the games against Argentina and New Zeland, is set for four to six weeks on the sideline.

The centre is currently out with a hamstring strain.