Garry Ringrose is set for an extended spell on the sidelines.
The Leinster and Ireland centre will be out of action for six weeks with syndesmosis of the ankle.
He suffered the injury in the Pro 14 victory over Ulster last weekend and it required surgery.
The issue will keep him out of both of Leinster's final Champions Cup pool games at home to Glasgow on Sunday and away to Montpellier the following week.
The Dubliner will also miss Ireland's opening Six Nations matches against France and Italy.
Tadhg Furlong is progressing well after a head injury and is set to complete return to play protocols this week.
The Wexford native is also nursing an elbow injury. James Tracy dislocated his elbow and will be out for between 4-6 weeks.
Adam Byrne will also miss the game and is due to see a specialist for a knee injury later this week.
Sean O'Brien, Joey Carbery, and Dan Leavy could be back in action this weekend as they step up their respective recovery programmes.