Conor Murray could miss Ireland's autumn internationals after he was cited for an alleged incident during Munster's win over Glasgow Warriors on Friday.
The British and Irish Lions scrum-half has been accused of 'striking with the elbow' by match citing commissioner Rob Flockhart, who issued his report on Sunday night.
Murray was involved in an altercation with Glasgow replacement Niko Matawalu during the second half of Munster's 13-6 victory at Scotstoun.
The 24-year-old appeared to lash out with his arm after denying Matawalu a try.
Referee Ian Davies referred the incident to the TMO to check whether the ball had been grounded, but no foul play was reported.
Glasgow referred the incident to Flockhart, who cited Murray for foul play contrary to law 10.4 (a) - striking with the elbow.
Matawalu was also cited for foul play contrary to law 10.4 (m) - act contrary to good sportsmanship (biting), after he was involved in an injury-time incident with Donncha O'Callaghan.
The loss of Murray to suspension would be another blow to Ireland coach Joe Schmidt, who has a mounting injury list ahead of next month's internationals against Samoa, Australia and New Zealand.
Key players such as Paul O'Connell, Sean O'Brien, Cian Healy, Rory Best and Keith Earls are all doubts, but Brian O'Driscoll and Mike Ross are expected to be fit for the Aviva Stadium clash with Samoa on 9 November.
Meanwhile, Munster and Ireland lock Donnacha Ryan has been linked with a move to France after he was spotted at Perpignan's Top 14 win over Bordeaux-Begles on Saturday.
The 29-year-old is out of contract at the end of the season and has attracted the interest of Perpignan and Clermont Auvergne.