Ireland and Leinster back row Sean O’Brien is looking at a four-month lay-off after it was confirmed he will undergo hip surgery.

The Co Carlow native has been struggling with an injury for some time now and will go under the knife to correct it following Ireland’s disastrous summer tour to New Zealand ended with a 60-0 defeat to the All Blackslast Saturday.

O’Brien was one of the few to come out of the series with any credit, and both the national and provincial set-ups will be keen for him to return to 100% as soon as possible.

Ireland manager said the flanker has been booked in for an operation this week.

"Sean is having some keyhole surgery on his hip to repair some cartilage damage within the next week or so, and the recovery period for this type of operation is 13 to 15 weeks," Kearney said.

"It means it could be up to four months. Obviously it's going to make him doubtful for November.”

As well as the Autumn Internationals, O’Brien will also miss the start of Leinster’s 2012/13 campaign.

"Like any operation there is some risk attached to it but the medics feel he will make a full recovery and that he will certainly be back towards the end of October and he should be back playing Heineken Cup rounds three and four in December,” Kearney added.