Sean O'Brien

Injured O'Brien ruled out of RWC

O'Brien did not feature for Leinster as they defeat Glasgow Warriors on Saturday to clinch the Pro14 title, although he did lift the trophy in his final match for the club.

The 32-year-old has agreed a deal to join newly promoted London Irish in the Premiership following the World Cup.

But O'Brien will not be involved in the tournament in Japan, Leinster revealed on Sunday, as he requires an operation to fix his hip.

Gatland cost us series - O'Brien

The Irish flanker said the team was over-trained ahead of the first test, which the All Blacks won 30-15, and the drawn third test.

"To be honest, I'd be pretty critical of it because I think we should have won the tour and we probably should have won it comfortably," O'Brien said in an interview with OffTheBall.com.