British and Irish Lions loose forward Sean O'Brien could miss the series decider against New Zealand after being cited for dangerous play.
O'Brien was cited for allegedly striking All Blacks wing Waisake Naholo with a swinging arm during the second half of the Lions' thrilling 24-21 win on Saturday.
In a statement on Sunday, the citing commissioner said the 59th-minute incident is "deemed to have met the threshold for a red card."
A panel will hear the case later on Sunday.
All Blacks star Sonny Bill Williams was sent off in the first half of what was a fiery second Test in Wellington.
The Lions' win levelled the series and set up a decider at Eden Park on Saturday.