Munster's Jerry Flannery, Keith Earls, Lifeimi Mafi and Barry Murphy all took part in non-contact training yesterday.
Keith Earls must wait for a further scan to determine when he will return to contact. Murphy is troubled by a hamstring problem.
Lifeimi Mafi is expected to be back for Magners League Round Three which means he should be in contention for the start of European action.
Prop Dave Ryan is out with a quad strain picked up in training while Tom Gleeson and Declan Cusack are struggling with groin injuries.
James Coughlan took a bang to his shoulder in the opening game against Leicester Tigers and it is hoped he will resume full training next week.