Fremantle superstar Nat Fyfe has revealed he tackled depression and anxiety last year as a horror run of injuries took a toll on his mental health.

Fyfe stepped down as Dockers captain this week after six seasons in the role, with the club yet to announce a replacement.

The decision came after a season in which the dual Brownlow Medal winner managed just seven games because of shoulder, back and hamstring injuries.

Fyfe watched from the sidelines as the Dockers played finals for the first time since 2015, and on Saturday revealed his struggles ran far deeper than the surface.

"What was happening on the outside, which was injuries, was just a small reflection of what was going on inside," Fyfe told the ABC.

"I had a fair bit to deal with. I had a good hard look at some of the ailments that we all face as humans in life, in terms of anxiety, depression and a bunch of those internal emotional things, which then came out as injuries.

"I had the shoulder that failed, then I got an infection, then I did my back, then I did multiple hamstrings.

"Internally I was cooked and I was just fighting my way through it, and I just kept breaking down."

Fyfe is physically fit again and says he has a fresh outlook as the 2023 season approaches, with Fremantle taking on St Kilda in round one.

The 209-game champion described his experiences throughout 2022 as a "profound teaching environment" that made him more resilient ahead of his 14th season at the top level.

"If you can go through that, find resilience out of it, come out the other side, I feel like that's the juice I now need for the backend of my career," Fyfe said.

"The past accolades were getting stale. There's only so long that you can parrot that you're a two-time Brownlow medallist from years ago.

"They were starting to get stale and I had no juice and motivation out of them, so a good hard look at rock bottom has fired me back up again."

Fyfe is set to continue spending more time in attack this season as the Dockers' midfield evolves, with young guns like Andrew Brayshaw and Caleb Serong taking the reins in the engine room.

The forward line role will again put a spotlight on Fyfe's goalkicking, which has let him down.

He said he is trialling new training techniques to improve his accuracy.

"It's my ultimate strength when I get it all lined up but it can tear me apart when it doesn't quite work," Fyfe said.

"This pre-season I'm working with a couple of different people more around connecting with that sort of inner voice and that fear, the stress, and getting a good handle on how you can put yourself in the optimal mindset and position to take the shot."