The defensive small played 14 games and booted 10 goals for the rebuilding Dockers in 2017, using his axing as motivation every time he played in purple.
"I faced footy mortality and I didn't really like the other side of it," Grey said about his delisting.
"So, every time I'm lacking motivation it's certainly something that inspires me to keep going.
"Having the opportunity to pull on the guernsey again was something that I really cherish, every time I get to play in the Freo top."