Naiyaravoro was cited for making a tackle in the air on Wellington Hurricanes' flyhalf Beauden Barrett during his side's 28-17 loss in Sydney on Saturday.
The 24-year-old was sinbinned by referee Chris Pollock but governing body SANZAAR reviewed the incident after the game and deemed it had warranted a red card and cited him to appear before a disciplinary hearing.
The 1.95m tall, 123-kilogram Naiyaravoro pled guilty at the hearing late on Sunday and judicial officer Robert Stelzner said he had reduced the entry point sanction of three weeks by two weeks after considering mitigating factors.
"I took into account the player's good record, his early guilty plea, the circumstances of the incident itself including the fact that it was unintentional, the players clear remorse (and) his opponents apparent acceptance of these facts," Stelzner said in a statement.
The Waratahs play the Blues at Eden Park on Friday and the 2014 champions must win to qualify for the playoffs.
Daryl Gibson's side are second in the Australian conference on 39 points, the same as leaders the ACT Brumbies, who face the last-placed Western Force in Canberra on Saturday.
Only the winners of the Australian conference can make the quarter-finals.
Four New Zealand teams, the Waikato Chiefs (51), Canterbury Crusaders (50), Otago Highlanders (48) and Wellington Hurricanes, (48) sealed four of the five postseason spots available from the Australasian group over the weekend.
(Reporting by Greg Stutchbury in Wellington; Editing by Peter Rutherford)
