Tana Umaga's Blues will be without Steven Luatua for four weeks after the All Black forward pleaded guilty to a dangerous tackle.
Luatua was red carded in Friday night's local derby against the Chiefs after catching Tim Nanai-Williams with a high shot right on the stroke of halftime.
He entered a guilty plea to Sanzaar's Foul Play Review Committee, accepting he had made direct contact with the Chiefs' centre's head.
Chairman Nigel Hampton indicated Luatua was fortunate to have only received a four week suspension, saying the actions were potentially worthy of six weeks on the sideline.
Hampton said the committee had taken "into account mitigating factors including the Player's early admission of guilt and his remorse for his actions, the Foul Play Review Committee reduced the suspension by two weeks".
Luatua, who is heading to English club Bristol and is in his final Super Rugby season with the Blues, is set to miss games against the Highlanders, Crusaders, Bulls and Western Force.
He is the first major New Zealand victim of a zero tolerance policy on high tackles enforced by World Rugby as it seeks to tackle the code's concussion and player safety record.