NAT FYFE'S transformation from skinny half-forward flanker to midfield beast has inspired teammate Hayden Crozier to add some more size to his frame this summer.

Crozier is heading into his fifth pre-season with Fremantle after he was selected with pick No.20 in the 2011 NAB AFL Draft.

The talented half-forward/midfielder has been on the fringes of the Dockers' best 22 for his first four seasons, playing 34 games since his debut in round 10, 2012. 

Crozier, who turns 22 later this month, was listed at just 68kg when he was drafted and is currently listed at 80kg.

He is keen to add more weight to his frame this summer while maintaining his running capacity.

"It's well documented I came in fairly skinny and a little pasty kid from Victoria," Crozier said.

"Seeing a guy like Nat Fyfe, the amount of size he's put on in a couple of years without losing any running ability, it's something to look up to. 

"I'm just trying to work hard in the gym and get my body right."

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Crozier spent Monday's training session at Fremantle Oval doing a lot of running away from the main group, but he described it as simply "ticking the legs over".

He ran laps with Lee Spurr for a decent portion of the two-hour session.

Fyfe and Harley Bennell were notable absentees from the session that mixed skills work with solid running. Fyfe spent most of the morning in the gym as he continues to work his way back from the broken leg suffered in the preliminary final against Hawthorn.

Bennell has trained indoors for the past two open sessions. He made a brief appearance to do some stationary skills on Friday but did not appear on the track on Monday.

Crozier said he did not know where Bennell was at with his program but stressed most of the pre-Christmas training block was devoted to players getting their bodies right and getting the kilometres in the legs.

Despite only playing 11 games last season, and missing out on playing in the finals series, Crozier signed a two-year contract extension to remain at the Dockers until the end of 2017.

He said he had learnt a lot about himself, being on the fringes of the 22, and believed he would play his best football at Fremantle.

"There's a lot of pressure for spots coming through," Crozier said.

"I'm happy staying here. I think I'll get the best out of myself.

"You just have to be patient coming in, especially in the situation I was in coming into a club that's going well.

"You've just got to wait your turn and try to play consistent footy at WAFL level."

Hayden Crozier has put on significant weight since his debut season in 2012. Picture: AFL Media