Collingwood star Scott Pendlebury has been ruled out of the AFL blockbuster against the Western Bulldogs as the reigning premiers count the cost of their mounting injury toll.
Pendlebury failed to complete training at Olympic Park on Wednesday, leaving the track early.
The 36-year-old has been battling an arm injury since last week's draw with Fremantle.
"Pendles won't play," Magpies coach Craig McRae told reporters immediately after Wednesday's training session.
"We anticipated he'd get through training and he'd be right, but he didn't get through training.
"We'll explore what that looks like. At this stage we're not sure, but no, he won't play.
"It's a big (blow). His leadership is critical, and with his experience he's hard to replace."
In better news for the Pies, McRae confirmed Jeremy Howe got through training and will return from a minor groin strain to bolster their tall stocks against the Bulldogs.
Howe started forward in Collingwood's win over West Coast in round nine before going down injured.
The versatile tall could be required in attack again, with Brody Mihocek (hamstring) and Mason Cox (concussion/knee) added to a long injury list last week.
Billy Frampton trained with the forwards and is another regular defender who could be swung into attack.
McRae conceded Collingwood are "swimming against the tide" with experienced stars Jordan De Goey (abdominal tendon), Jamie Elliott (vascular), Tom Mitchell (plantar fasciitis), Will Hoskin-Elliott (hamstring) and Dan McStay (knee - season) also sidelined.
But the Pies' third-year coach welcomed the opportunities those injuries are affording to younger players, and is looking forward to what the senior players' returns could present later in the season.
"I'm really excited to see more opportunities for some, and there'll be a period when they'll come back," McRae said.
"This is not permanent ... there's a period we have to get through, and what about when they come back? I'm excited for that.
"There will be a lot of players coming back that haven't been beaten up for 25 rounds."
The Bulldogs have also been hit hard by injuries, losing key forward Aaron Naughton (knee), Ed Richards and Anthony Scott (both concussion) for the Collingwood clash.
Defender James O'Donnell is expected to return after missing last week's loss to ladder leaders Sydney through illness.