FREMANTLE fans might feel nervous if Alex Pearce pinch-hits in the ruck against West Coast, but the valuable Dockers defender is confident in his body and prepared to play anywhere in search of his first Western Derby victory.

Pearce could have two crucial roles in the historic derby at Optus Stadium on Sunday.

The 200cm key backman is in All Australian form after shutting down some of the AFL's elite power forwards, and shapes as the perfect match-up for Derby dominator Josh Kennedy.

But with Matt Taberner (fractured metatarsal) out of Freo's line-up, Pearce might be called up to support Aaron Sandilands in the combative ruck duel against Nic Naitanui and Scott Lycett.

MATCH PREVIEW: Fremantle v West Coast

"The last Derby I played in when Aaron went down with those broken ribs (in round three, 2016) I was the second ruckman, so I had a fair bit of a go against Nic back then," Pearce told AFL.com.au.

"It is quite tough, but you've just got to commit and give it your best shot, I guess. 

"I actually enjoy the ruck. It's just good fun being around the ball a bit more. 

"We'll see, it might be something down the track that I might do more of, but for now I'm pretty focused on playing in defence."

Pearce hasn't gone head-to-head with Kennedy before and was planning to lean on mentor Luke McPharlin this week for advice. 

Kennedy looms as a major stumbling block for the Dockers after bagging 16 goals in the past three cross-town clashes.

However, Pearce has the size and speed to nullify the Eagles match-winner, who needs one major to break Peter Sumich's club record of 514 goals.

"He's obviously one of the best forwards – if not the best forward – in the game for the last few years," Pearce said. 

"He's an extremely hard worker, he works up the ground really well, and he's quick on the lead. 

"You can't let him get a sniff around goals because he's got a great set shot and doesn't miss too many. 

"There's always little things with each player each week that I'll try and change in my game to stop them but in general, stick to my focuses and try to be physical, try to play each minute pretty hard and not switch off is the main thing." 

Pearce's plans are clearly working.

In a stunning comeback from nearly two years out of the game, he has conceded only six goals to his opponents this season, according to Champion Data.

The 22-year-old went through tough times when he re-broke his leg in January last year, however he credits the support of family, friends and Freo for helping him get through the mental battle and return a better player.

"That second break was the hardest part, because we didn't really know why it broke that second time," Pearce said.

"There was a lot of uncertainty and obviously being out of the game that long, there's always a chance you might not come back and that started to creep in for a while." 

But any anxiety disappeared after his return game in the JLT Community Series. 

"It's feeling great. I haven't even worried about it at all," Pearce said. 

"From the pre-season on to now it's not something that gets sore any more at all. 

"It's forgotten, in a way.

"I've got a lot of confidence in it and it's not something that plays on my mind at all now, which is great." 

Pearce, elevated to the leadership group this year, is quick to credit Freo's backline group for making his tough jobs easier this season.

The Dockers' defence has evolved rapidly over the past 12 months, becoming one of the most damaging rebounding units in the game.

Recruit Nathan Wilson has been outstanding, while Luke Ryan, Stephen Hill and Connor Blakely are attacking the game with run and carry, helping Freo average 103 points per game at the club's new home, and only 71 against. 

"That’s been our focus for a lot of the year: our drive from the backline and taking the game on, and getting it in the hands of those good users," Pearce said.

"That will be the same this week. We're not going to shy away, we're going to keep trying to attack from there and also maintain our defensive structures we've got in place." 

The build-up to the 47th Western Derby has been embroiled in controversy over the Ross Glendinning Medal's future, with WA footy fans divided over the issue.

It has added some extra spice to the clash and Pearce, who has played in two Derby defeats, is expecting the pro-Dockers crowd to be at fever pitch as Freo attempts to end a five-game losing streak against the Eagles.

"We know our fans are very passionate about us and probably against the Eagles a bit, but we've prepared as we have each week," he said.

"We'll try and take the emotion out of it as much as we can, but we know that our fans won't be able to do that."