Lee Thomas will take no further part in London Wasps' bid for Amlin Challenge Cup glory - and a fourth European title.
Thomas ruptured his Achilles in the Premiership match against Exeter Chiefs and has been ruled out of the key back-to-back contests with Bayonne and January's clashes with Newport Gwent Dragons and Rugby Mogliano.
Wasps lead Pool 3 after two maximum points wins but the double header against Bayonne, who are just a point behind them, will determine the group winner to qualify for the knock-out stages.
The first leg for the 2003 tournament champions and 2004 and 2007 Heineken Cup winners is at Stade Jean Dauger and Wasps Director of Rugby Dai Young rues the long-term loss of centre Thomas.
"We are bitterly disappointed to lose Lee who was really starting to find his feet in a Wasps shirt," said Young.
"I thought he was excellent against Leicester and played very well against Exeter until he was forced off and it's a big blow to lose him for so long.
"We really feel for him as I know he was thoroughly enjoying his first few months here but we will have to focus on getting him back fit and ready for next season. He is a good character and once he is over the disappointment of being injured he'll be an important guy to have around with all of his experience."
