Rugby: Cardiff will definitely be without Jamie Roberts when they take on Leinster in the Heineken Cup quarter-finals this weekend. The Welsh centre will require surgery after suffering a recurrence of his knee injury in Glasgow last Friday and is set to be out of action for up to six months.

The Grand Slam winner injured his knee last autumn but had been fit enough to help Cardiff reach the last eight of the Heineken Cup and played a huge part in Wales’s Grand Slam winning campaign. However, after taking another knock in Scotland at the weekend he has been advised to have an operation later this week.

As well as missing the remainder of Cardiff’s season, Roberts is also ruled out of Wales’s summer tour to Australia.

“First and foremost, I'm pretty devastated to be missing this weekend's Heineken Cup quarter final match against Leinster, in what is our biggest match of the season,” he said today. “It's a match I've been looking forward to for a long time but unfortunately my body hasn't quite allowed me to be a part of such a huge occasion for us as a region.

"I originally injured my knee in Paris playing against Racing Metro after returning from the World Cup. With the fantastic help from the medical staff at the Blues and Welsh Rugby Union, I was able to rehab my knee well enough to get me through a handful of games for the Blues and the successful Grand Slam Six Nations campaign with Wales.

"However, following my injury in the match against Glasgow on Friday night I've been advised by the knee surgeon that my knee is now not stable enough to continue playing and potentially risk further injury to the knee. The decision has been made for me to have an operation on the Anterior Cruciate Ligament (ACL) later this week."

"It will mean a minimum of roughly six months away from the playing field. I suppose it's a chance for me to get my body fully right for what is a huge season for both club and country, with a certain carrot at the end of it too."

Without Gavin Henson, who was sacked yesterday following a drunken incident on a flight back from Glasgow on Saturday morning, Cardiff are expected to bring in Dafydd Hewitt or Gavin Evans to start alongside Casey Laulala in the Blues midfield.