Cardiff - Wales centre Jamie Roberts is set to be sidelined for six months after being told to undergo knee surgery, his club side Cardiff Blues said on Tuesday.
As well as ruling him out for the rest of the European season, Roberts's injury means the Grand Slam-winner will miss Wales's tour of Australia in June.
"The decision has been made for me to have an operation on the anterior cruciate ligament (ACL) later this week," Roberts said in a Cardiff Blues statement on Tuesday. "It will mean a minimum of roughly six months away from the playing field."
News of Roberts's injury came the day after the Blues sacked his fellow Wales centre Gavin Henson for his drunken behaviour on the flight back from Scotland following their Celtic League defeat by Glasgow on Friday.
However, the Welsh capital club do have inside centre cover in Gavin Evans or Dafydd Hewitt ahead of this weekend's European Cup quarter-final against Irish defending champions Leinster.
Nevertheless, the loss of the 25-year-old Roberts, capped 44 times by World Cup semi-finalists Wales and twice by the British and Irish Lions, with a ligament injury at such a key stage of the season is a huge blow to Cardiff.
"First and foremost, I'm pretty devastated to be missing this weekend's Heineken (European) Cup quarter-final match against Leinster, in what is our biggest match of the season," Roberts said.
"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."
Roberts, explaining the origins of his knee problems, which flared up once more against Glasgow, said: "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 (WRU), 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."
Roberts, still aiming to be a member of the British and Irish Lions squad in Australia in 2013, said there was a silver lining:
"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.
"It will also allow me to continue my focus on the final year of my degree in medicine and the finals I'll be sitting next March."