Cameron was subbed out of Friday night's match against Richmond due to a knee complaint sustained in the dying minutes of the third term, with the Magpies pulling the trigger on their tactical change at the final break.
Already without Mason Cox for the coming rounds due to a hematoma detected close to his ribs this week, Collingwood coach Craig McRae could be forced to select a non-recognised ruckman for their Round 4 bout with Brisbane following Cameron's setback.
Third-string tall Aiden Begg is currently sidelined indefinitely with a back injury, with the early signs for Cameron not spelling welcome news for the Magpies.
"We've had a bad weekend in the ruck stakes," McRae said.
"Lost Mason for a period of time and now it looks like Darcy will be out for a significant period.
"We'll find out more, but initial diagnosis is a high-grade MCL (sprain)."
Collingwood's fourth ruck option will be Supplemental Selection Period recruit Oscar Steene, who only joined the Magpies in February.
McRae hinted that Steene may need some more time before being utilised at the top level, with the Magpies hoping to have a trick up their sleeve to aid their ruck woes.
"I'm rapt with how he's developing," McRae said of Steene.
"We set people up to succeed. We'll have to weigh up whether that's the case with him. Whether it's too early.
"It's not impossible, but I want to set players up to succeed and it might be a bit early for him, but we'll have to wait and see."
Collingwood could call on either Ash Johnson, Dan McStay or Billy Frampton to take on the brunt of the ruck workload in the absence of Cameron and Cox, with both Johnson and McStay relied on to help defeat the Tigers at the MCG.
Collingwood will face Brisbane at the Gabba next Thursday night as they look to continue their undefeated start to the 2023 season.