Scotland forwards Ross Ford and Jonny Gray face missing the rest of the World Cup after they were both issued with three-week bans.
Hooker Ford and lock Gray were punished by a world rugby after their two-man tip tackle during Saturday's clash with Samoa dumped the Pacific Islanders' flanker Jack Lam on his head.
The Dark Blues pair - both vital members of Vern Cotter's squad - are now set to miss Sunday's quarter-final clash with Australia unless they decide to appeal.
They have 48 hours to challenge the ruling or face missing out on the rest of Scotland's campaign.
A spokesman for the national team said they were " disappointed" by Judicial Officer Christopher Quinlan QC's decision, adding: "We will consider carefully the full written judgement before making a decision on any future action."
Both Ford and Gray denied committing an act of foul play but Quinlan ruled otherwise.
World Rugby's statement on the case said: "Tackles involving a player being lifted off the ground and tipped horizontally and were then either forced or dropped to the ground must be dealt with severely by match officials and all those involved in the disciplinary process.
"With respect to the sanction, the Judicial Officer deemed the act of foul play merited a low-end entry point, namely four weeks. The Judicial Officer added one week for aggravation due to the need to deter this type of dangerous foul play.
"However, taking into account mitigating factors including the players' conduct prior to and at the hearing, their expressions of regret, exemplary characters and excellent disciplinary records, the Judicial Officer reduced the suspension to a period of three weeks in respect of each player.
"In the context of Rugby World Cup, three weeks equates to three matches and therefore neither player will be available to play for the remainder of Rugby World Cup 2015. Any remaining sanction not applied in the tournament context will revert to weeks for the players' respective club fixtures."
Meanwhile, Gordon Reid hopes Scotland can script themselves a victory of Hollywood proportions when they take on World Cup A-listers Australia.
The Glasgow prop is gearing up for a blockbuster quarter-final with the Wallabies at Twickenham.
Few - if any - seriously believe that Vern Cotter's side can upstage the Aussies in London and clinch a first semi-final slot in 24 years.
But Reid is refusing to write off his team and has taken heart from the underdog tales which have inspired so many movie classics.
He said: "It would mean everything to get that chance to play this weekend. The win against Samoa in our final group match and even just being there to have those memories was amazing.
"It's not just any team we are up against this weekend, it's Australia - one of the biggest teams in the world.
"But we've got a bit of belief about us now. Our first objective was to get through to the quarters and now it's knock-out rugby. Anything can happen.
"Everyone is writing us off as underdogs. I don't care. It's awesome. Just look at the movies. It's always the underdog who wins - just look at the Mighty Ducks. We can be those Mighty Ducks.
"This is the position we relish being in. Hopefully we can go out and do ourselves proud at Twickenham.
Scotland suffered an RBS 6 Nations whitewash earlier this year but have responded with an impressive display of single-mindedness, shrugging off the Japanese shock troops, dodging another banana skin laid down by the United States before withstanding a surprise Samoan onslaught to escape Pool B, with defeat to South Africa their only blemish.
The battle with the Pacific Islanders in particular has served to solidify Scottish resolve as they found a way to win despite shipping four tries in the St James' Park thriller.
And wing Tommy Seymour insists that while the performance in Newcastle was not perfect, it has reinforced his team's confident stride.
"The belief is there in the squad," he said. "W e regrouped quickly after the Six Nations and put the past behind us. We went through warm-up games and the group stages of this competition collecting a few wins along the way and that breeds confidence.
"We had to win a different way against Samoa compared to the wins over Japan and US. It was a narrow margin but that certainly does help create a psyche where you become aware of of the ability in yourself to win tight games.
"So going up against Australia, we know it's going to be a hugely physical game and one we will have to be at our peak to win.
"The Samoa game has warned us about the things we have to do right. But we know when the clock is ticking if we do the right things we can come out on top."