FREMANTLE coach Ross Lyon hopes the fallout from the bitter Western Derby hasn't become a distraction for his players and instead fuels their desire against bottom-placed Carlton on Sunday.

Both the Dockers and Eagles have expressed their need to move on now that Andrew Brayshaw has flown back to Melbourne to recuperate from his injuries, and West Coast midfielder Andrew Gaff has been rubbed out for the season.

Fremantle has a golden opportunity to notch an eighth victory – and equal last year's tally – against the struggling Blues at Optus Stadium, and Lyon called on his troops to refocus.

"You've got to bring a passion. My expectation … is the same passion (from the Derby is) brought to the Carlton game this weekend," Lyon said.

"That's the most critical thing, and the same level of desperation and commitment, and that will stand us in really good stead.

"That's the challenge for our group. You can't live in the past, you've got to move on.

"It's a potential distraction, if you let it be. We've got to let it fuel our preparation and our desire to perform well.

"In the end, the outcome, what we produce on the weekend will maybe tell us have we been distracted or have we been hard-nosed pros and got on with it."

Debate has raged about a send-off rule after Gaff's punch and, while he isn't convinced, AFL CEO Gillon McLachlan said introducing a red card would be looked at.

"I've expressed a personal view that I think in terms of dealing with these issues like this, it can create as many issues as it solves," McLachlan told 3AW on Friday.

"Steve Hocking, at the end of the year, will look at all the (possibilities).

"He'll look at the red card as he should, as all the other things, to say 'Can we improve our judicial system and our accountability system?' He'll consider it and all of that.

"It's my personal view that it's got some challenges."

Lyon didn't have a strong opinion either way.

"You hear the commentary, there's lots of pros and cons, and I'm sure it will be dissected," he said.

"We've just got to make sure we don't make knee-jerk reactions."

Lyon was keen to look ahead rather than in the rear-view mirror, and said the Dockers will be forced into three changes against the Blues, with Stephen Hill (quad), Darcy Tucker (back) and Brayshaw (jaw) all sidelined.

Former Box Hill pressure forward Sam Switkowski is in the mix to be Freo's eighth debutant this year after overcoming hamstring issues.

"(He has) really good speed, really good repeat effort, really committed to the defensive actions, which the best teams are featuring, if you think Richmond, in particular," Lyon said.

The Dockers couldn't consider injury-plagued Harley Bennell for his long-awaited comeback after he suffered another calf tear two weeks ago.

With only three rounds left, it appears increasingly unlikely the 25-year-old will add to his two Freo appearances since his trade from Gold Coast at the end of 2015.

"I expected it to be a week, it didn't quite be that. Peel have got the bye. It was probably a moot point, because it's highly unlikely you pick someone who hasn't played much in 12 months after missing and straight in," Lyon said.

"We'd expect him to be available next week to play football."

Superstar captain Nat Fyfe (hamstring) will sit out a sixth-straight game against under-pressure Carlton, which copped a 105-point thrashing from the Giants last round, but is set to return next round for a tough trip to face Geelong.