The injury-hit Wellington Hurricanes and Waikato Chiefs face being without their talismanic captains for their Super Rugby semi-final clash next weekend.
Dane Coles was taken from the field with what appeared to be serious rib damage when the Hurricanes downed the Coastal Sharks 41-0 and Sam Cane was concussed when the Chiefs thrashed the Western Stormers 60-21 this weekend.
The 'Canes meet the Chiefs in Wellington in the first semi-final on Saturday with the second semi-final between the defending champions Otago Highlanders and the Golden Lions in Johannesburg.
Coles grimaced in pain as he was assisted from the field early in the second-half when the Hurricanes became the first side to record a shutout in Super Rugby playoffs.
"It doesn't look terribly good," 'Canes coach Chris Boyd said of Coles' injury.
"When I spoke to our physio, they said it was really about pain and comfort. These things can come right quickly or they can linger, so I think it's an absolute wait-and-see."
Cane required stitches after he suffered a blow to the head in the first-half as the Chiefs ran rampant against the Stormers in Cape Town.
Although coach Dave Rennie described the injury as "minor", Cane did not play the second-half and will have to undergo tests before he can be cleared to play.
"He's going to have to go through protocols," Rennie said. "He was pretty clear and didn't have any symptoms post-game but we'll need to see how he scrubs up."
The Chiefs return to New Zealand on Tuesday where Rennie will get an update on the availability of backrower Michael Leitch, who has been sidelined for two months with a broken thumb.
"We'll be hopeful to get him back on the field," Rennie said. "The timeline was really the final, but there's a chance he might come back earlier. I'll know a bit more once we get home."