McCarthy left the Dockers in August after being told he wouldn’t receive a contract for the 2021 season, with his exit being mutual for both parties.
“I’ve always said that from day one, I like Collingwood,” McCarthy told The Western Australian.
“Obviously I wish I would have played for Freo for the rest of my career.
“If I’m not going to play, why would I go back over to another hub and sit there for five weeks?
“JL (Justin Longmuir) is doing a good job down there. They’re going to be a serious side in the next couple of years, trust me.”
The Fremantle forward has kicked 99 goals from his 70-game career.