A new foot injury has Geelong premiership defender Jack Henry in doubt for the rest of the AFL season.
But Collingwood are holding out hope defender Nathan Murphy might be available for Saturday night's blockbuster against the Cats.
Melbourne also confirmed on Tuesday night forward Harrison Petty will not play again this year because of his foot injury.
The Cats said scans had shown Henry has a mid-foot Lisfranc ligament injury after he was stood on during Saturday night's home win over Port Adelaide.
It is different to the foot fracture he had during the pre-season, which sidelined him until round 10.
The Cats are unclear how long Henry, who has played 11 games this season, will be out of action.
“We were surprised to see the results of the scans as the incident occurred innocuously during the game," said club football boss Simon Lloyd.
"Our medical team will now work through the options available to provide the optimal outcome for Jack and determine how long he will be sidelined for.
“We are all disappointed for Jack, he is a very important player for us, not just with his flexibility to play a number of roles but because of his calm head and stability he provides down back."
Gary Rohan (ankle) is expected to play against Collingwood while Tom Hawkins ran laps on Tuesday and is expected to train on Wednesday as he returns from a hamstring injury.
Meanwhile, Magpies coach Craig McRae said Murphy was making a rapid recovery from the ankle injury he suffered in Saturday's loss to Hawthorn.
Young gun Nick Daicos was sidelined for six weeks with a knee injury and it was initially forecast Murphy would be sidelined for two to three weeks.
“On Murphy, who was ruled out, he’s a chance to play. I don’t know how,” McRae told SEN
“He’s got to get through training tomorrow (Wednesday). He was no chance on Sunday and he’s some chance now on Tuesday.
"Time might be against him being a Friday night game, but he’s not so much 2-3 weeks (away) now.”
Adelaide also announced utility Chayce Jones will have surgery on a Lisfranc fracture and is out for the rest of the season.
Petty has suffered the same fate after he was hurt in Sunday's win over North Melbourne.
"'Petts' has significant damage to his Lisfranc which means he won't play again this year," Demons football boss Alan Richardson said.
"It's a fairly significant rehab, but we're really confident long-term that he'll be fine.
"It's disappointing for the team, disappointing for the club given where we are at with the stage of the season, but look he'll be a real pro with his rehab like he always is."
But the Demons are hopeful star onballer Clayton Oliver will return from a hamstring injury on Saturday against Carlton for his first game since round 10.
