Collingwood captain Darcy Moore will miss the Anzac Day blockbuster against Essendon as he battles vertigo symptoms related to an inner ear issue.
Moore didn't train in the Magpies' main session on Wednesday after previously missing Monday's training.
On Tuesday, Moore said he was feeling fine and only missed Monday's training with a cold - but he was ruled out by coach Craig McRae a day later.
"Darcy won't play," McRae said.
"Darcy's got a bit of an inner ear issue. We're not sure exactly what it is. He's got a bit of vertigo symptoms at the moment.
"We've had scans, he's probably off to see a specialist now to see what's going on there but he won't play."
Last Thursday, Moore was on the receiving end of a nasty collision against the Brisbane Lions, when Logan Morris pushed him into the path of Jeremy Howe, who was in a marking contest with Cam Rayner.
Howe's knee split the cartilage in his ear, but Moore was cleared of concussion and McRae insisted that his absence was not related to the knock.
"No, we've done the protocol a couple of times, or the assessment a couple of times - there's no issue there," he said.
"It's just something that's sort of lingered early in the week and it's not going away so he hasn't had the ability to train and we're getting to the bottom of it and hopefully we'll find out today what we're dealing with.
"I just chatted to him prior to training and he said it comes on and it goes away.
"Again, I haven't experienced vertigo but he's using that language."
Moore leaves a huge hole in the high-flying Magpies' defence ahead of Friday's clash at the MCG.
Defenders Charlie Dean and Jakob Ryan are among the recall options for a match-up with Essendon tall Peter Wright.
Either Nick Daicos or Brayden Maynard will step up as captain in Moore's absence.
McRae won't look to temper Dan Houston's aggression as the former Port Adelaide star returns from his second suspension for a high bump in as many seasons.
"I'm only getting to know Dan's game ... he plays on the edge a little bit and I'm noticing that," McRae said.Â
"But we like this aggression in the game and obviously there's rules for a reason, so he's got to play within those.
"He's an incredible organiser on the field for us and clearly talented with ball in hand. We're excited to have Dan back."
Jordan De Goey is continuing to build his fitness and form after multiple injury setbacks.
"We're well aware he's still a little away (from his best) - I'm not sure exactly on the timeline," McRae said.
"We're managing him. This is the first week he's played and trained, and I thought his training today was exciting for our fans to see. He's moving better every week.
"It's a work in progress, and we're playing the long game. We want Jordy to be fit and well."