Leinster's Champions Cup winning centre Robbie Henshaw has been ruled out of Saturday's Guinness PRO14 semi-final against Munster.
The Ireland international, who missed the Grand Slam decider against England after dislocating his shoulder scoring a try against Italy, suffered a knee injury in Saturday's nail-biting 15-12 win over Racing 92.
Out-half Johnny Sexton is also being monitored due to a light groin niggle, while match-winning captain Isa Nacewa has a calf injury that is also being closely watched by the province.
Leinster coach John Fogarty was unable to provide a prognosis on Henshaw's injury.
"We're not quite sure yet," he told RTÉ Sport's Damien O'Meara.
"He's going to get assessed this week and we'll know more. Johnny felt a little twinge in his groin. Again, he's going to be assessed today."
The scrum coach was more confident about Nacewa's involvement - given his intention to retire at the end of the season.
"Isa has two games left in his career. He's the type of person who'll do all he can to get on the field. The job the medical staff is to make sure he's actually fit because he's going to do everything he can to play!
"He's picked up something small. We'll see how he is."