A week after re-signing with Collingwood, Will Hoskin-Elliott needs knee surgery and is in doubt for the start of the AFL season.
The forward said on Monday he had had knee soreness for several weeks.
He will have an operation on Tuesday and is unsure about being ready for the Magpies' March 22 opener against Geelong.
"It hasn't gone away, so we're just going to try and clean it out that way," he said of surgery.
"It's about a three- to four-week recovery, so it will be touch and go.
"You'd rather miss the front couple of games (of the season) than the back end.
"It's frustrating, but I'd rather do it now."
Defender Jeremy Howe is also recovering from leg surgery, but ruckman Brodie Grundy is back training with the main group after a toe injury.
Forward Jordan De Goey is in a moon boot after suffering a foot injury last Friday during an intra-club hit-out.
The Magpies will have a better idea at the end of this week how long he will be out of action.
