Ireland flanker David Wallace is facing a minimum of six months on the sidelines following the knee injury that ended his World Cup dream.
The 35-year-old flanker suffered serious ligament damage in a tackle by Manu Tuilagi during England's 20-9 warm-up success at the Aviva Stadium on Saturday.
Wallace underwent surgery on the injury in Dublin on Sunday night, with Leinster's Shane Jennings being called in as his replacement in Declan Kidney's squad.
And Munster, Wallace's province, have confirmed in a statement on their website that he "is expected to be sidelined for at least six months".
That diagnosis means Wallace may miss the entire pool stages of the Heineken Cup, which end in January, as well as a significant chunk of the RaboDirect PRO12 season.