France centre Benoit Baby has been cited for an incident during Ireland's 26-19 Six Nations defeat at Lansdowne Road on Saturday.
The 21-year-old Baby, who was playing in his first international, was warned by referee Tony Spreadbury after head-butting Ireland captain Brian O'Driscoll in a ruck in the 48th minute of the game.
The referee also awarded a penalty to Ireland which flyhalf Ronan O'Gara converted.
Baby was named man of the match after scoring his first international try during the first half, blasting through the Irish defence to cross over after a 40-metre run.
He was cited by independent citing commissioner Bill Dunlop of Scotland. He faces a three-man disciplinary hearing on Wednesday which will be chaired by Robert Horner of England.
"I knew immediately I shouldn't have done that," said the Toulouse centre after the game. "For a few minutes, I really thought I would get a yellow card. It would have been a disaster for my first selection."