Munster flanker Alan Quinlan has been cited for allegedly making contact with the eye or eye area of Leinster captain Leo Cullen in Saturday's Heineken Cup semi-final.
The independent citing commissioner John Byett decided Quinlan has a case to answer after television cameras appeared to catch him making contact with Cullen's right eye.
Quinlan, 34, has been called to appear before a European Rugby Cup disciplinary panel, which is to be appointed 'as soon as is practicable'.
If Quinlan is found guilty of the offence - commonly termed eye-gouging - he faces missing the British and Irish Lions tour to South Africa.
The minimum sanction is a 12-week suspension.
Earlier this season Northampton and Ireland flanker Neil Best received an 18-week ban and in 2007 Saints hooker Dylan Hartley was suspended for 26 weeks.
Quinlan, 34, was a surprise selection in Ian McGeechan's original 37-man Lions squad.
If suspension was to rule him out of the tour, McGeechan could look to England and Leicester flanker Tom Croft or Wales captain Ryan Jones.
Cullen remonstrated with Quinlan at the time but he was not prepared to comment on the alleged incident after the final whistle at Croke Park.
But Quinlan received glowing character references from his Munster and Lions captain Paul O'Connell and the Leinster coach Michael Cheika.
O'Connell did not see the alleged incident but said after the game: 'If it looked bad I am sure there was nothing in it.
'He is a tough player. It is the one thing he hasn't got in his record book.'