Cameron was the star of the show with a season-high 10 goals, feasting on the Cats' territorial dominance in their thumping 19.17 (131) to 8.8 (56) win at GMHBA Stadium on Friday night.
But Darcy faces a nervous wait for further assessment after he fell to the ground under no contact in the second quarter and played no further part in the game.
The 22-year-old was fortunate to dodge an anterior cruciate ligament tear when he hurt the same knee in April last year, and the club will send him for scans to determine the full extent of the latest damage.
"It's obviously a pretty serious knee injury," Bulldogs football operations manager Matthew Egan told Fox Footy at halftime.
"The mechanism didn't look great, but we just can't confirm everything.
"Unfortunately I've been here before where I've said it's a serious knee injury and we think ACL, and it wasn't.
"So we need to be positive and just wait for the scans."
The Bulldogs trailed by 38 points when Darcy limped off the field early in the second term and were never in the hunt.
Tom Liberatore (concussion), Rory Lobb and James O'Donnell (both hamstring) were further casualties on a horror night for Luke Beveridge's side.
Dogs captain Marcus Bontempelli was troubled by a right knee issue but played out the match.
Geelong celebrated significant milestones for Mark Blicavs (300 games) and Jake Kolodjashnij (200) in a win that lifts them to a 4-2 record, level with the Bulldogs, who have lost two straight games after a hot start.
Key defender Kolodjashnij produced a highlight in the final quarter with his fifth career goal, bringing many in the 33,200-strong crowd to their feet.
Cameron kicked two majors in the opening term and five in the second, taking his career tally to 750 and helping Geelong storm 57 points clear by the main break.
It was the heaviest half-time deficit the Bulldogs have faced in a dozen seasons under Beveridge.
Bailey Smith was influential against his former club with 33 disposals, 11 clearances and one goal, while Max Holmes (28 touches), Oliver Dempsey (27) and Shaun Mannagh (21) also shone for Geelong.
Captain Patrick Dangerfield made a positive return from a calf injury with two goals from 19 touches in his second game of the season.
Cats coach Chris Scott was understandably pleased with his side's performance, but tempered his excitement amid the Bulldogs' injury woes.
"We're awake to the fact that they had their challenges and it got worse for them as the game went on," Scott said.
"I can't imagine their box being any more flat than ours when Sam Darcy went down.
"You're not a real football person if your heart doesn't go out to individuals and the club in situations like that.
"It's easy to not get carried away with our performance when you think about the challenges the opposition had."
The Bulldogs could have turned their toes up after losing Darcy and Liberatore, but stemmed the bleeding for a period with four goals to one in the third quarter.
Aaron Naughton kicked three goals, Ed Richards tallied 30 touches and six clearances, and Matthew Kennedy (27 touches) fought hard.
"We're trying to process it on two fronts," Beveridge said.
"The (injury) carnage is pretty traumatic, so in a sense I was pleased with the way the players for patches were able to at least sort of steady things a bit as they were losing teammates.
"But the way we started and played the game, we were on the back foot. Geelong's contested game and the pressure they put on, we didn't manage it too well."Â
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