Cardiff Blues could be without influential back row forward Maama Molitika for the whole of their Pool 5 Heineken Cup campaign.
The Tongan international damaged his pectoral muscles in the recent win over the Scarlets and is expected to be out of action for up to four months. The injury means the Blues could kick-off their European season without a complete back row unit.
Already ruled out until December is Wales and British & Irish Lions flanker Martyn Williams, who underwent shoulder surgery after returning from South Africa this summer, while No 8 Xavier Rush is struggling with a dislocated finger. Rush was another injury victim in the win over the Scarlets.
The Blues launch their Heineken Cup season with a home game against the Harlequins next week and then have to travel to Sale Sharks in Round 2. They then face Toulouse in back to back matches in December.
Blues coach Dai Young, who led his side to the semi-finals last season, is also sweating on the availability of Lions centre Jamie Roberts for the game against the Quins. He suffered a soft tisssue injury to his neck in the game against the Scarlets and has been sidelined for 7-10 days.
On the positive side, Young looks set to have Wales wing Tom James back in harness in time for the big Euro kick-off. James, who scored the dramatic try in the semi-final at the Millennium Stadium last season that took the game against Leicester Tigers into extra-time and then penalties, underwent surgery during the summer.
Finals Edition: Listen to the best guide to the European Rugby Cup Finals weekend in Dublin, which sees Leinster Rugby take on Stade Francais Paris at the RDS on Friday night in the Amlin Challenge Cup Final and then ASM Clermont Auvergne tackle Toulon in an all-French affair at the Aviva Stadium on Saturday.