Collingwood has traded defender James Aish to Fremantle, with the 23-year-old moving to his third club in seven years.
The Dockers have sent their future second-round and fourth-round picks to the Pies, while Collingwood has attached pick 69 and a future third-round pick to Aish.
Aish played 32 games for the Lions between 2014-15 before moving to Collingwood, and has played 50 games for the Pies since joining the club.
He was a member of their grand final side in 2018.