Out-half Johnny Sexton and lock James Ryan are on course to be fit for Ireland's Guinness Six Nations match against Italy on Saturday week.
The Leinster pair both missed Sunday's defeat to France after suffering head injuries in the opening-round loss to Wales.
However, head coach Andy Farrell confirmed that Caelan Doris will be absent for the "foreseeable future."
Leinster number 8 Doris, 22, left the Ireland camp before the first game to be assessed for "some symptoms that could be associated with concussion".
"We are expecting to [be without him] for the foreseeable future," said Farrell.
"Caelan is getting well looked after, seeing the right people, getting the right advice and making sure that he’s comfortable on his return to play.
"That’s still in process but we don’t intend to see him back anytime soon."
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Prop Dave Kilcoyne (calf) also missed out against Les Bleus but is expected to be available.
A number of players were released from the camp for this weekend's Guiness Pro14 games.
"Their health is pretty good coming back," said Farrell of the squad members who remained in national camp.
"There are one or two lads with bangs and bruises but nothing too serious. I’m sure by the start of next week we’ll have a full bill of health hopefully."
Asked about the news from the France camp, who have gone into isolation following confirmed Covid-19 cases in their management team, including head coach Fabien Galthie, Farrell said that testing has increased in the Irish set-up.
"We’ve all been thoroughly tested," said the 45-year-old.
"We normally get tested twice a week. We had some down time on Monday and we got tested in our own time there and all that’s come back negative.
"All the lads got tested again on Wednesday to come into camp, fit [today] and we’re getting tested again on Friday so they’re literally up to their nose in it really regarding testing.
"We are doing everything that we can to make sure that we do the right thing."
Follow Italy v Ireland (kick-off 2.15pm, Saturday, 27 February) via our live blog on RTE.ie and the RTÉ News app or listen live on RTÉ Radio 1's Saturday Sport. Highlights on Against the Head on RTÉ2 and RTÉ Player.