Leinster backrow Rhys Ruddock will be out of action for between four to six weeks. The in-form Ruddock fractured his arm in Leinster's European Champions Cup win against Harlequins at the Aviva Stadium on Saturday.

There is only a slim possibility that he will be available for Leinster’s round five and six games in the competition at the end of January at home to Castres and away to Wasps. But he will now definitely miss the series of interprovincial Pro12 derby matches over the festive period.

"Rhys broke his arm," said Leinster manager Guy Easterby. "It looks like he will be out for about four to six weeks. There are bumps and bruises around the camp but nothing else significant and anyone who is sore from the weekend should be available."

“Yeah it’s absolutely frustrating,” he added. “It’s a really difficult time for players when they are in that injured phase. It’s tough.”

Easterby pointed to Dave Kearney, who injured himself on the way back from injury. Leinster are otherwise operating a wait and see policy with players such as Richardt Strauss, Shane Jennings and Gordon D'Arcy.

“Hopefully a few of those will be able to come back into the mix,” added Easterby. “And make it a more even selection across the board.”

Seán O’Brien, however, is not an imminent returnee. The Ireland and Leinster flanker was seen running around in Aviva at the weekend prior to the match, but his recovery from a shoulder injury will not be hurried.

“His recovery is going well,” said the Leinster manager. “But the sort of injury he had is something that we are not going to rush because we want to get it right. If that means we take it conservatively then that makes sense because we are looking at the long term picture.”