Vaea Fifita's red card for a high tackle on Dan du Preez was not overturned at a SANZAAR judicial committee hearing.
The Hurricanes will be without Vaea Fifita for their Super Rugby quarter-final after the loose forward was given a three-week ban following his dismissal against the Sharks.
New Zealand international Fifita was shown a red card for a high tackle on Dan du Preez five minutes from the end of his side's 30-17 victory at King's Park on Saturday.
Hurricanes head coach John Plumtree felt Fifita was unfortunate to be given his marching orders, but the decision was not overturned at a SANZAAR judicial committee hearing on Tuesday.
Plumtree will be without the 26-year-old for the two remaining matches of the regular season against the Lions and the Blues.
Fifita will also be unavailable when the Hurricanes attempt to secure a place in the last four against a quarter-final opponent that is yet to be determined.