Ireland will give CJ Stander, Rob Kearney and Simon Zebo every chance to prove their fitness for Saturday's Test with Australia.
Flanker Stander and full-back Kearney are working through head-injury checks after concussions, while Zebo continues to suffer the after-effects of cramping during Saturday's 21-9 defeat to New Zealand.
Ireland are already without Johnny Sexton and Robbie Henshaw for the weekend fixture and assistant coach Simon Easterby said: "We will know later in the week as they [Stander and Kearney] go through those protocols.
"Simon has managed training today and got through some work.
"He, like some other players in the group, are being managed, to get them right for Thursday, when we can select the team based on who is available."
Fly-half Sexton misses Ireland's final autumn international with a hamstring strain, while Henshaw has been ruled out through concussion.
Utility back Keith Earls trained fully on Tuesday after missing the All Blacks defeat with a dead leg, while lock Ultan Dillane has beaten a minor knee issue.
"Keith has managed to train today, Ultan was carrying a bump from his performance against Canada so those guys are back on board," said Easterby.
"The players put themselves through a hell of a workload at the weekend.
"It's important we get them right in the first part of the week, so we can build up to Thursday and Friday and get them in a really good physical and mental state for Saturday."
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