Jonathon Sexton could be out of this weekend's Heineken Cup quarter-final clash with Harlequins.
But Lienster do have the right to appeal the decision of an Irish Rugby Football Union disciplinary committee who banned the player for two weeks after upholding a citing complaint.
Sexton had been cited under law 10.4 (c) for an alleged kick on Munster player Lefeimi Mafi in the 70th minute of the Magners League meeting on April 4, 2009.
The hearing took place in Ravenhill, Belfast at 4.30pm on Tuesday and was heard under a disciplinary committee chaired by Hugh Logan who was assisted by Stephen Hilditch and Neil Jackson.
Having studied the match footage and heard all available evidence, the disciplinary committee upheld the citing and that the player was guilty of an act of foul play. The committee imposed a two week suspension starting from today, Wednesday 8th April up to and including Wednesday, 22nd April.
Leinster coach Micheal Cheika will also be without South African prop. Cheika expalined. "CJ (van der Linde) is not going to make it this week. His injury is slightly different to the previous one. It's the same type of area, but it's not as serious. We're hoping that within a couple of weeks he might make his return.
"Brian (O'Driscoll) trained pretty well today and he has a good chance of being fit. Luke (Fitzgerald) was only partially in training today, so we'll make a final decision on him on Friday. Bernard (Jackman) hasn't trained this week and he's probably more of a doubt than the others. We'll check him on Friday and assess exactly where he's at with his swollen knee and make a decision then. Our medical staff is working around the clock to try to take down some of the swelling which is unrelated to his other injury.
"Ollie (le Roux) has a lot of experience. He knows our system and he certainly doesn't lack confidence, so I'm sure, if we decide to put him into the fray that he will be more than capable of fulfilling the role that I might ask him to fill."
Finals Edition: Listen to the best guide to the European Rugby Cup Finals weekend in Dublin, which sees Leinster Rugby take on Stade Francais Paris at the RDS on Friday night in the Amlin Challenge Cup Final and then ASM Clermont Auvergne tackle Toulon in an all-French affair at the Aviva Stadium on Saturday.