Sean O'Brien: Ireland flanker ruled out of Rugby World Cup

Sean O'Brien has won four European Cups and three league titles since joining Leinster in 2008

Ireland back row forward Sean O'Brien has been ruled out of the Rugby World Cup as he will be sidelined for up to six months recovering from hip surgery.

A statement released by Leinster on Sunday indicated that O'Brien will have surgery "in the next few weeks".

O'Brien lifted the Pro14 trophy on Saturday after Leinster beat Glasgow 18-15 in the final at Celtic Park.

The 32-year-old British and Irish Lions flanker is joining London Irish later in the year.

O'Brien made his Ireland debut in 2009 and has won 56 caps despite struggling with a string of injuries.

"It is a huge blow for Ireland and Sean will be bitterly disappointed," said former team-mate Stephen Ferris.

"Hip surgery is a pretty big operation and he has had a few issues with his hips over the last number of years so fingers crossed he is able to get it all sorted out over the next few months."

Injury denied O'Brien a place in Leinster's squad for the Pro14 decider but he still collected the silverware after the win.

His future involvement in international rugby is in doubt given Ireland's preference to select players who are contracted to play for the Irish provinces.