Jonathan Sexton is set to return to the Ireland side for Sunday's Six Nations visit of Italy, but Iain Henderson has been ruled out.
Ulster lock forward Henderson tested positive for COVID-19 during Monday's routine round of squad testing.
The IRFU confirmed on Wednesday afternoon that Henderson has left the Ireland camp, and will complete his period of isolation at home.
No other positive tests have been reported within the group, and they will continue to be tested up until Sunday's game at the Aviva Stadium.
In better news for Andy Farrell, Sexton looks set to start against the Azzurri.
The out-half conducted the captain's press conference on Wednesday, proclaiming himself "good to go" having missed the defeat away to France a fortnight ago with a hamstring strain.
Sexton's absence in Paris raised more questions over whether he should remain Ireland's go-to no.10 en route to the World Cup.
But the 36-year old shrugged off suggestions the hamstring injury could prove chronic.
"As an older athlete - if you want to call me that - or, rugby player, you need to look after yourself well and better," Sexton said.
"I don't think I could've done much different in terms of my preparation, or warm-up or whatever - just one of those things.
"Maybe I was carrying a knock from the Wales game, that I was trying to train with, that could've had a bearing - you just don't know for sure.
"Anyway, it was a minor enough thing - I bounced back well from it, thankfully. I've had some good training at the back end of last week, and then fully today with the lads.
"I got some kicking in as well, back end of last week and early this week. [I'm] in a good place now, and fit for selection."
With Sexton declaring himself fit, it's almost certain that Joey Carbery will return to the replacements' bench for the game with the Azzurri.
But the elder statesman of the Ireland squad feels his understudy performed well under pressure in Paris a fortnight ago.
Sexton told OTB Sports, "To get called in late it's always tougher, I suppose."
"He would have been preparing the same anyway, knowing him, he's a very good professional and always does his prep right.
"I don't think it would have affected him too much. He was composed on the day and did well.
"It's good for him - having a tough time with injury - to get back, and he's played a few games now in the summer, and Argentina and France. He's getting those games in the international arena under his belt, and he'll only be much better for it."