Collingwood skipper Darcy Moore could "potentially" miss the remainder of the season, according to coach Craig McRae.
Moore returned from the US after an intense training camp in a bid to rectify his spate of soft-tissue injuries.
"He's progressing. Slowly, but he's progressing," McRae said.
"There's evidence he's moving in the right direction, but there's still a long way to go. Pleasing, he got a good running session today. But as far as I'm aware, the timeline is the timeline. I don't know what that is. I don't think (the high-performance team) know."
McRae confirmed leader Brayden Maynard is a week-by-week prospect after he dislocated his shoulder in the King's Birthday clash.
The club has opted against surgery to keep Maynard's season alive, just as they did with forward Will Hayes, who suffered the same injury.
Defender Isaac Quaynor is in doubt to play Richmond on Saturday at the MCG.
"He left the track with a bit of a sore foot, so I don't know if he got stomped on or he just landed a bit awkward," McRae explained.
"He's going to be a bit of a watch the next 24 hours, we'll see what that looks like.
"We'll plan with and without him at the moment. We'll see how that goes."
Veteran Scott Pendlebury will return to the senior side, while Harry DeMattia will be brought into the extended squad ahead of Thursday's 5pm teams deadline.
DeMattia has yet to debut for the Pies, but after spending more time as a forward in the VFL, he has impressed with his pressure and scoring threat.
Angus Anderson is unlikely to regain his spot after his shock omission from the Port Adelaide clash.
Anderson was sent to the VFL in a bid to play more permanent midfield time, according to McRae, after spending the majority of his outing against Melbourne as a forward.
