Auckland Blues flanker Steven Luatua has been suspended for four weeks for a head-high tackle during their weekend Super Rugby match against the Waikato Chiefs.
The 15-Test All Black, who is moving to English club Bristol at the end of the Super season, was sent from the field just on half-time after he felled Chiefs' wing Tim Nanai-Williams.
Luatua tweeted a public apology after the game, won by the Chiefs 41-26, and pleaded guilty when he appeared before a disciplinary panel on Sunday.
Committee chairman Nigel Hampton said the player's "early admission of guilt and his remorse for his actions" merited reducing a potential six-week suspension to four weeks.
Luatua was shown a red card for thrusting out an arm and hitting Nanai-Williams around the throat when the Chiefs player did not have the ball.
World Rugby is intent on eliminating head-high tackles and has directed match officials to show zero tolerance.
Blues coach Tana Umaga said before the hearing that he accepted there should be no leniency.
"If you can't adjust your tackling style or tackling discipline, it's not going to be good for the team," Umaga said.
"We can't question Steven's want to do well for this team it is just a technical thing that he needs to work on."