The 35-year-old flanker had surgery on his injured right knee in Dublin on Sunday, and is expected to be sidelined for at least six months.
His Munster and Ireland colleague Felix Jones, who also had his Rugby World Cup hopes dashed by injury, faces a lengthy spell in rehab too.
Jones injured his right foot in the recent home defeat to France. The 24-year-old full-back is due to see a specialist next week when a clearer indication of how long his recovery will take can be determined.
Meanwhile, Munster train this morning in Cork ahead of their RaboDirect PRO12 opener next Saturday against the Newport Gwent Dragons.
Head coach Tony McGahan is expected to announce an extended squad later this afternoon, which will include John Hayes and Tomas O'Leary.