HIGH-FLYING Collingwood defender Howe will miss most of the season after reaggravating his hamstring injury, needing surgery.

The Pies have also confirmed teammates Jordan Roughead and Nathan Murphy will miss this weekend's game against Sydney with the AFL's mandated 12-day concussion rest after both suffered head knocks during Saturday's win over North Melbourne.

All indications were Howe would return this weekend, with coach Nathan Buckley saying mid-last week he only needed to get more training sessions under his belt, but he pulled up sore on Saturday and will have scar tissue removed from the area.

"Jeremy trained exceptionally well last Thursday and all the signs were that he would return against Sydney this week," Collingwood general manager of football Graham Wright said.

"But on the weekend, he felt a grumble and we decided to have him re-examined today.

"Jeremy is understandably disappointed. He put so much work into recovering from a serious knee injury in 2020 and to lose a significant part of another season hurts."

Murphy was subbed out of the Pies' win over the Roos, and while Roughead cleared his match-day concussion test, the club said it is not the sole defining factor.

"The (concussion) protocols involve a fair bit more than the match day test and with all of the factors considered our doctors determined that it is in Nathan’s and Jordan’s best interests to miss," Wright said.

"We spoke with the AFL for the sake of clarity, and support the view that decisions on concussive episodes are often complex and in need of caution."

The Pies broke a five-game losing streak against North Melbourne, but currently sit in 16th position with two victories from eight games.