Queensland Reds flanker Conner Vest suffered a fractured neck while co-captain Liam Wright has also been ruled out for the season after a dramatic loss to the Highlanders.
Vest remained in a Dunedin hospital on Saturday, scans revealing a fracture of his C7 vertebrae in a shock diagnosis after he had walked off the field in the 29th minute following a tackle.
Wright dislocated his shoulder in the act of scoring a try in the seventh minute while fellow co-captain Tate McDermott (concussion) was the third Reds player scratched in the first half of the 35-30 loss.
Vest will return home on Sunday for further assessment and specialist opinions before a decision is made on the management of his injury.
Wright won't play again this season, but the Reds say McDermott hasn't displayed concussion symptoms and remains a chance of playing in the final regular-season round in Fiji.
There was no review of the tackle that felled Vest, while the Reds are privately seething after a high, no-arms tackle on a runaway James O'Connor from Highlanders five-eighth Eddie Burns also went unpunished.
The Reds had already earned a sit-down with World Rugby after having three previous requests for reviews of high contact on their players waved away by Super Rugby Pacific governing body SANZAAR.
Chasing their first win in Dunedin since 2013 and second since 1996, the Reds led 14-0 and then 27-14 thanks to some exhilarating and powerful rugby.
But the Highlanders surged back into the contest and another controversial try, awarded despite two possible knock-ons and a forward pass in the build up, put them ahead with 14 minutes to play.
Tom Lynagh put the Reds back ahead with a clinical penalty goal from 45 metres out and 10 metres in from touch, before a last-minute try sunk the visitors.
It left them clinging to seventh spot and potentially needing a win in Fiji to qualify for finals.
"I'm super proud of the guys, just with the injuries and the guys who stepped up," coach Brad Thorn said.
"We got a bonus point out of it, we're still alive and onto the final round.
"Heck yeah (the bonus point will be critical)."
Thorn, who won't coach the side next season, reserved special mention for the son of Wallabies great Michael Lynagh in his first start since the third round.
"I just thought Tom Lynagh, 20 years old, he's got that last name, who used to do the same thing," he said.
"Ice cool, just nails it from 40-something out.
"He just announced himself, I felt.
"Winning the game would have been a good moment for him, it still was, I felt."