The ruck contest between Aaron Sandilands and Nic Naitanui will be pivotal to the outcome of Sunday's Carlton Draught Derby, Fremantle midfielder Danyle Pearce says.

Win tickets to Sunday's game

Both ruckmen are in fantastic form and their match-up, as well as the contest between likely back-ups Zac Clarke and Scott Lycett, will be important in giving each midfield an advantage on Sunday.

Pearce said he backed the Fremantle's ruck combination of Sandilands and Clarke to quell Naitanui's influence.

"It’s going to be a great contest," Pearce said.

"Nic Nat can jump and we need to make sure we get on top of him and nullify him as much as possible. It'll go a long way to help whichever midfield win."

Clarke has been in doubt due to ongoing knee soreness but he did run laps at Freo's open training session at Fremantle Oval on Wednesday.

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Clarke did not appear at all during last week's Wednesday session, yet still played against Geelong, but will face a fitness test ahead of Sunday's clash with West Coast.

If Clarke fails to get up, Pearce backed one of Jack Hannath, Michael Apeness or Jon Griffin to come and do the job.

“We’ve got a couple of young boys down at Peel (Thunder) playing really well so the next person will just slot in and do their job," he said.

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Matthew Pavlich, Luke McPharlin, Paul Duffield, Michael Walters and Garrick Ibbotson were also withdrawn from the skills session on Wednesday. They did some light running before returning to the rooms.

Nat Fyfe didn’t train on Wednesday but emerged from the rooms to sign autographs for the fans at the end of the session.

Fyfe has polled 20 out of 20 votes in the AFL Coaches' Association Player of the Year award across the first two rounds. The 23-year-old has also jumped into outright favouritism for the Brownlow Medal. Pearce said he was glad to have Fyfe on his team in this form.

"He's playing absolutely fantastically," Pearce said.

"The whole of Australia is seeing it. I'm just glad he's on my side."

The former Port Adelaide defender said there were as many as four or five options to replace the suspended Hayden Ballantyne this week but it appears Hayden Crozier and Tendai Mzungu are the frontrunners.

Youngsters Max Duffy, Connor Blakely, Lachie Weller and Ed Langdon all trained with the development group for large portions of Wednesday's session, while Crozier and Mzungu worked with the senior players as they practiced inside 50 delivery and goalkicking.