New Zealand's Adam Thomson and Australia's Rob Simmons could both miss the rest of their countries' European Test tours after being cited.
All Blacks flank Thomson has been cited for stamping on the head of Scotland loose forward Alasdair Strokosch three minutes into the second half of the world champions' 51-22 victory at Murrayfield on Sunday.
Meanwhile Simmons has been reported for a dangerous 'tip tackle' on France's Yannick Nyanga during the Wallabies 33-6 defeat in Paris on Saturday.
Hearings for both Simmons and Thomson will be held before independent International Rugby Board-appointed judicial officers in London on Wednesday.
Thomson was sent to the sin-bin by French referee Jerome Garces on advice from Irish touch judge Simon McDowell.
Television replays indicated Thomson brought his boot down on Strokosch's head, suggesting he was fortunate to escape with only a yellow card and Irish citing commissioner Murray Whyte has decided further action is required.
Thomson now faces a ban that could rule him out of New Zealand's remaining Tests against Italy (November 17), Wales (November 24) and England (December 1).
Asked after the game if Thomson should have received a straight red card, Scotland coach Andy Robinson - himself a former England flank - replied: "You would think so."
If he is suspended, Thomson could face a ban of between three to eight weeks.
Meanwhile Australia replacement lock Simmons was cited by South Africa's Freek Burger for his challenge on Nyanga midway through the second half of Saturday's international at the Stade de France.
During the course of that match, Welsh referee Nigel Owens was heard apologising to the France team for the officials' failure to issue a red card for the challenge on Nyanga as they could not identify tackler Simmons.
Australia next play England at Twickenham this coming Saturday.