Impending fatherhood and a want to deliver on a promise he made his close-knit family has changed Nathan Wilson's world.

Wilson, one of Greater Western Sydney's first-ever signings when he was taken as a pre-listed 17-year-old, is now officially a Fremantle player after the Giants and the Dockers agreed on a deal to send him back to his home state.

The 24-year-old wasn't due to come out of contract until the end of the 2018 season and he'd become an important member of the GWS backline, playing 45 games over the past two seasons.

But news earlier this year that his partner Stevie was pregnant forced Wilson to re-evaluate his life and career goals, and he knew it was time to return to Western Australia.

Wilson told AFL.com.au his decision to request a trade to Fremantle shortly after the Giants' preliminary final loss to Richmond was all about family.

"From when I was a little kid I've always said that if I ever made the big stage I wanted to play some footy in Perth, and I promised my family when I left for Sydney that one day I'd come back," he said.

"There was always the want there to come home; I didn't know when it would happen exactly, it could have been next year or in three years' time.

"But it's done now and it's going to be great for my family to come and watch me every second week, especially my little nephews and nieces."

Losing the dashing defender in the prime of his footy life is a blow for the Giants, but Wilson was full of praise for senior coach Leon Cameron and footy manager Wayne Campbell in particular, who agreed to work with the Dockers to make sure he got his wish.

"Leon and Wayne were great when I told them, they've got young families themselves so they knew how I felt," he said.

"I was honest with them from the get go, the Giants have been so supportive of me for the last seven years and I can't thank them enough.

"It was hard to tell the boys as well but they knew my situation.

"It wasn't like I was going behind their backs and turning down a new contract, they knew that Stevie and I needed to come home for support.

"I had a great night with them at the best and fairest to say my goodbyes."

Wilson will spend the next few days holidaying in Bali where he owns a tattoo parlour, before returning to Sydney to work through some logistics, and officially end his time as a Giant.

He'll link up with childhood friend Harley Bennell and another former Giant Cam McCarthy at Fremantle, along with the likes of Michael Walters, and Stephen and Bradley Hill, who are also familiar faces.

He said that Dockers coach Ross Lyon has already spoken to him about how wants the gun defender to play next year, and revealed he'd given him some advice about dealing with the scrutiny that comes with being an AFL player in Perth.

"He told me to keep focused on footy and not to get sidetracked which is a big thing for me, and it will be a challenge but I can't wait," he said.

"I'll be looking to fill the same role I've played with the Giants for the last two years, and that’s running off half back and reading the play, then using the ball as best I can and taking the game on.

"I play on instinct and Ross knows that, so I'm looking forward to getting into it.

"It's really exciting especially with the new stadium opening next year, but more importantly I'm stoked to be home."