Sean O’Brien set to miss the start of the Six Nations

Leinster backrow Sean O’Brien is set to sit out at least the first game of this year’s Six Nations due to a hip injury.

Leinster confirmed that their backrow forward has undergone a hip procedure, saying in a statement: “Sean O’Brien saw a specialist this week for the tightness in his hip as it hadn’t responded to treatment as we would have liked.

“As a result he had a small procedure and the target is to have O’Brien back available during the Six Nations window.”

The British and Irish Lions star, who has played just four games for Leinster this season, missed the province's recent Pro14 derby wins over Munster, Connacht and Ulster after limping off during the victory against the Chiefs at the Aviva Stadium on 16 December.

Leinster also revealed that Adam Byrne is to have surgery on a knee injury that he suffered on Ireland duty in November.