Irish international Rhys Ruddock could miss the rest of the season.
The Leinster flanker suffered a hamstring injury during Sunday's Champions Cup victory over Exeter.
Reports claims he has suffered a grade 3 tear which will keep him sidelined for a least three months.
Ruddock captained Ireland in the recent win over Fiji and scored a try in the victory over South Africa.
Leinster are optimistic that Johnny Sexton will overcome a quad injury to retain his place in the team this weekend's game against Exeter at the Aviva Stadium.
Andrew Conway and Rhys Marshall are doubts for Munster's trip to Leicester due to concussion.