Update 1pm: Leinster centre Garry Ringrose is set for a lengthy spell on the sidelines having undergone an operation on the ankle injury he suffered in Saturday's win over Ulster.
The 22-year-old is expected to be out of action for around six weeks.
He is set to miss the upcoming Champions Cup Pool games against Glasgow and Montpellier, and Ireland's Six Nations fixtures against France and Italy.
Leinster Senior coach Stuart Lancaster says it is harsh on Ringrose, who only recently returned from shoulder surgery.
"Disappointing for the team but disappointing for Garry in particular because you know how hard he worked to get back fit and he played his best game, I think, against Ulster," said Lancaster.
"It's one of those injuries that is just uncontrollable really in a sport like rugby.
"He's pretty philosophical about it so he will be back in a few weeks and we'll go from there."
Meanwhile, there is better news on Tadhg Furlong.
The Lions Prop failed a Head Injury Assessment during weekend's match at the RDS, but is said to be making good progress through the return to play protocols.
Furlong is also receiving treatment on an elbow injury, but has yet to be ruled out for the weekend's clash with Glasgow.
Earlier: Garry Ringrose looks set to miss the first two games of the Six Nations.
The Ireland and Leinster centre is expected to be sidelined for six weeks after suffering an ankle injury in Saturday’s Pro 14 win over Ulster.
Ringrose will also sit out the upcoming Champions Cup Pool games against Glasgow and Montpellier.
The 22-year-old made his return to play just over six weeks ago after being sidelined for five months with a shoulder injury.
He underwent surgery to repair the issue in July following Ireland’s summer tour against the USA and Japan in which he started all three matches.