The injury will sideline him for Munster's league derby with Leinster this Friday, their back-to-back Heineken Cup clashes with Llanelli Scarlets next month and he is also in danger of missing the province's final Heineken Cup pool games against Wasps and Clermont Auvergne in January.
The back row has proved to be an unlucky area for Munster this season with regards to injuries - flankers John O'Sullivan (cruciate knee ligament) and Jake Paringatai (broken cheekbone) are currently on the injury list, while Ireland openside David Wallace has missed matches due to ankle and leg injuries so far this season.
Munster are also resigned to being without their captain Paul O'Connell for such a vital part of their season.
A persistent back injury has meant the Ireland and Lions second row has not featured for the province since his return from the World Cup. He is scheduled to return to training in three to four weeks' time.