England lock Charlie Ewels has been banned for three games after being sent off in the Six Nations defeat against Ireland on 12 March.
Ewels was shown a red card after just 82 seconds following a clash of heads in an attempted tackle with James Ryan.
It was the earliest dismissal in the Championship's 139-year history.
He will miss England's final game of the tournament against France, and matches against Sale Sharks and Worcester Warriors for his club Bath.
Following the incident, Ewels has since admitted foul play at a hearing before an independent judicial committee.
Six Nations Rugby said the ban was halved from the usual term of six weeks because of the 26-year-old's "relatively unblemished" disciplinary record and his "remorse" and "contrition" over the offence.
In a statement, the tournament organisers said: "Having acknowledged mitigating factors including, the player's early acceptance of the red card, his remorse and contrition for his offending, his relatively unblemished disciplinary record over a long playing career and his good character and conduct at the hearing, the committee reduced the six-week entry point by three weeks."
Ewels has the right to appeal the decision within three days and also been offered the chance to take part in a Coaching Intervention Programme to "substitute the final match of his sanction".
Matches Ewels will miss:
England v France - 19 March
Bath v Sale Sharks - 26 March
Bath v Worcester Warriors - 30 March