Xavier Rush has been ruled out of Cardiff Blues' Heineken Cup opener against Calvisano.
The All Black star has failed to recover from knee surgery ahead of the Welsh region's trip to Italy on Saturday.
But Blues coach Dai Young insists talismanic number eight will win his race against time for the crunch Euro tie against Gloucester on October 19.
Young said: "Xavier's injury is a big blow. He is a vital player for us for us but his knee flared-up after the Connacht game.
"We now hope that Xavier will be back for our game with Gloucester at the Millennium Stadium the weekend after next."
The Blues will also be without Wales wing Tom James who has a groin problem but British Lion Gethin Jenkins and Tom Shanklin return.
Blues: Ben Blair; Leigh Halfpenny, Jamie Robinson, Tom Shanklin, Gareth Thomas; Nicky Robinson, Jason Spice; Gethin Jenkins, T Rhys Thomas, Gary Powell, Deiniol Jones, Paul Tito, Maama Molitika, Martyn Williams, Andy Powell.
Replacements: Taufa'ao Filise, Gareth Williams, Scott Morgan, Robin Sowden Taylor, Richie Rees, Ceri Sweeney, Jamie Roberts.
As the countdown continues for RWC2015, Tournament Chief Executive Debbie Jevans visited the Millennium Stadium to discuss preparations for the eight matches and reveal the positive news that 100,000 tickets for games at the home of Welsh rugby have sold in the last seven days.
Jason Harries is targeting a first win on the World Series circuit this season with Wales. The series returns to action this weekend in Dubai where Harries is part of a team hoping to build from its efforts in round one in October.
Wales skipper Jevon Groves says his side have addressed a few points from Gold Coast and aim to 'hit the ground running' in the next two rounds of the World Series, kicking off with this weekend in Dubai before heading off to South Africa next week.
Wales Sevens manager Steff Thomas is hopeful his side can build from a quarter-final spot in the opening round of the World Series in Australia when his side take part in the forthcoming double header in Dubai and South Africa.