Murray sustained a knee injury in Ireland's game against Argentina, while O'Connell is continuing to rehab from the back problem that ruled him out of the three international fixtures this month.
Munster coach Rob Penney is still hopeful that both players will be available for the back-to-back Heineken Cup games against Saracens next month, but O'Connell has yet to return to the pitch for any squad sessions since breaking down in Ireland camp.
"Paul's injury is a frustrating one," said Penney.
"It is a case of waiting and seeing with him. Paul will, like last time, know when he's ready. In the lead-up to the Racing game he was back on the pitch, but he has yet to make it outdoors so far.
"Conor has played a lot of footy recently and he took a bang to his knee.
"It's not a serious injury and it's a good time for him to get a rest this weekend."