Leinster match winner Johnny Sexton is facing a race against time to be fit for the Heineken Cup champions' semi-final clash with Toulouse on Saturday, 1 May.
The Irish international outside half landed seven out of eight kicks for a match tally of 19 points in his side's sensational 29-28 home quarter-final win over ASM Clermont Auvergne at the RDS last Friday night.
But no sooner had he left the field than the doctors found he had a problem with his jaw and he was taken to hospital for a minor operation.
"Johnny had a little operation. We will just see how he pans out, but I would say it is probably going to be a few weeks," admitted Leinster coach Michael Cheika.
"It's a little crack in his jaw. He is pretty good really, but it is a pretty obvious injury and he can't just go out there and say 'I'll be alright', strap it up and away you go.
"I would say it is fairly touch and go as to whether he plays in the semi-final. Rob Kearney is pretty much the same.
"He is not as bad as we first thought. When you get carried off on a stretcher it isn't ideal but, again, he will be touch and go in that environment and he is definitely out of this week's match.
"Brian O'Driscoll is out of this week's match as well, although we are probably a little bit more hopeful of getting him right in the next couple of weeks."
Leinster get back into Magners League action this weekend - they currently lead the league by seven points with a game in hand - and face two of the Grand Final Play-Off candidates ahead of their trip to Toulouse.
They host the Ospreys, who lost their Heineken Cup quarter-final against Biarritz Olympique last weekend, in Dublin on Friday night and then travel to Glasgow the following weekend.
Then it will be back to the Heineken Cup for the clash with three-times champions Toulouse as Leinster try to keep alive their dream of making it back-to-back titles.
"Everything varies from week to week. Before the quarter-finals the commentators were saying Toulouse haven't been great this year and after the game they were saying 'Oh my God, they are geniuses!" said Cheika
"You know what their potential is because their playing roster hasn't changed a whole lot over the years, except that it has probably got a bit stronger and they have added some new blood.
"They have got amazing depth from the bench. Knowing the way of thinking down there a little bit, I don't think they mind too much that it is us. I think they would prefer it to be us than, say, Munster.
"Maybe they think we are still a little bit tender. That might be the impression of Leinster in France and, also, everyone in France seems to think that we were a bit lucky to win the other day and don't see the work that went into the match either."
As part of the build-up to next month's Cardiff 2014 Heineken Cup and Amlin Challenge Cup finals weekend, ERC has joined forces with the WRU, Cardiff Blues and adidas to develop an annual grassroots community rugby programme targeting young players.
The Ulster Rugby full back, Jared Payne (No 15), has been suspended for two (2) weeks following an independent Disciplinary Hearing in Dublin arising from the Heineken Cup quarter-final match against Saracens at Ravenhill Stadium on Saturday, 5 April.