Sean O'Brien and Jared Payne will undergo late fitness tests on Saturday morning to determine their availability for Ireland's Test against Australia.
The Irish have suffered a host of injuries and O'Brien and Payne could be added to the list as both are suffering from "lower limb tweaks."
However, Ireland assistant coach Andy Farrell was optimistic that the dup would be passed fit to play.
Ireland have already called up flanker Peter O'Mahony back into the squad on Friday to cover O'Brien, while Munster utility back Rory Scannell would step up should Payne fail to recover.
Ireland are already without the injured Johnny Sexton and Robbie Henshaw.
"We've had a couple of guys that's had a couple of niggles, and the captain's run is normally just a stretching-legs type session," said Farrell.
"We made a couple of decisions this morning to rest Jared Payne and Sean O'Brien and see how they are in the morning. We'll have a discussion in the morning about their situation. They both have just lower-limb tweaks, that's what normally happens during the week.
"You pick things up on the way from the game, through the week and so on. The main session was yesterday and we decided to give a couple of players more time. We've kept Peter O'Mahony here, and we've got Rory Scannell as well covering for Jared Payne. All the main work's been done already, that's why we are resting them, to give them every chance to feel 100 per cent."