Declan Kidney's injury woes continue and the Irish boss looks like he will be without Shane Horgan, Fergus McFadden and Jerry Flannery for the summer tour to New Zealand and Australia.
Horgan was a late withdrawal from Friday night's 29-23 defeat to the Barbarians due to a stomach bug, which forced him to go to hospital, while McFadden suffered a broken jaw.
The IRFU released a statement on Saturday confirming that McFadden has been ruled out as his injury will require surgery and a recovery period of six to eight weeks.
Flannery is staying in Ireland to allow the leg injury that saw him substituted in Thomond Park to be monitored.
Meanwhile, Ireland suffered injury-time heartbreak as the curse of the French struck once again in the Junior World Championships.
Simon Zebo's superb 80th-minute try and James McKinney's nerveless touchline conversion looked to have earned a hard-fought draw for Allen Clarke's charges.
But there was to be one final twist as Gilles Bosch struck for a penalty five minutes into stoppage-time and the French held out to win.
Irish prospects of emerging from Pool B got even tougher as a rampant England chalked up a bonus point in beating Argentina in the second game of the afternoon and it's the English who are next up for Ireland on Wednesday.
But Clarke is retaining hope of emerging from the group stages.
“Obviously we're disappointed with the result,” he said.
“There was no lack of effort but there are aspects of our game that we need to improve upon and we're aware of that.
“We've a changing-room that's hurting at the moment, but the group's still alive — very much alive — but we've no option now, but to focus on winning our next game.”
After a blistering start, Ireland somehow ended up going in 12-6 down at the break, with Queen's out-half James McKinney replying to four Jean-Marc Doussain penalties.
Ireland improved after the interval and the excellent McKinney manoeuvred his side into a 15-12 lead going into the final quarter.
The French emptied their bench early and the reinforcements had the desired effect as Bosch set up the field position for Les Bleus to pound the Irish line, with No 8 Antoine Erbani eventually crashing over. The replacement out-half converted, before adding a penalty to extend the lead to seven.
But Ireland didn't lie down and substitute Noel Reid launched a brilliant length-of-the-field counter that led to Zebo touching down in the corner.
McKinney stayed cool to deliver from the touchline.
With plenty of stoppage-time looming, the win definitely looked on, but then a Reid clearance went straight into touch, Ireland infringed at the line-out and Bosch sent over the winner.
Dejected skipper Rhys Ruddock admitted his side face an uphill battle to reach the semi-finals.
“It's definitely more difficult now,” he said.
“But we're still playing to get out of our group and we know we just have to play a lot better to do that come England.”
IRELAND: A Conway; D Hudson (N Reid 70), E Griffin, N Spence, S Zebo; J McKinney, J Cooney (M Heaney 76); J O'Connell, N Annett (D Doyle 73), S Maguire (B Cagney 73); D O'Callaghan, B Marshall (B Hayes 73); R Ruddock, D Ryan, P Butler.