Four of Collingwood's senior players - Tom Phillips, Josh Thomas, Mason Cox and Matthew Scharenberg - face an uncertain future at the club, reports The Herald Sun.

The off-contract Scharenberg is set to explore a move back to South Australia, while the other three players are contacted until the end of next season

The Magpies were defeated by Geelong in last week's semi-final coming off a grand final and preliminary final appearance in the two previous seasons.

Coach Nathan Buckley declared that the Pies would be 'aggressive' in the upcoming trade period as they look to improve in certain areas.

"I know key forward is an area, but we still need to replenish our midfield and find a wave of guys that are going to come through there," Buckley told reporters.

"That might be a target area.

"Outside run, high forwards and wingers might be an area we have to look at.

"I think understanding yourself is the most important step you need to take before you work out what you need and we think we've got a pretty good handle on that."

Collingwood are embarking on a crucial off-season as they also look to re-sign a host of uncontracted stars amid a tight salary cap, including Darcy MooreJordan De Goey and Brody Mihocek.

The Herald Sun reports that the Pies are also keen on free agent Jeremy Cameron if he opts to leave GWS.