Bennell's AFL career is likely to be over after he suffered what the club described as a "significant right calf tear" while playing in the WAFL.

The 26-year-old has been plagued by calf injuries since crossing to Fremantle at the end of 2015, and his current one-year deal expires at the end of this season.

The Dockers still don't know whether Bennell's latest setback is season-ending or not.

But even if he is able to make it back near the tail-end of the WAFL season, it seems unlikely the Dockers will offer him a new deal.

Lyon has been a huge supporter of Bennell over the past four years, and said he was feeling for the former Suns star.

"It's heartbreaking really, so close to senior football. It's very upsetting," Lyon said.

"We're just putting our arms around him, mapping out a rehab plan and keeping Harley close. It is devastating, but all we can do is support and guide."

Bennell was playing his fourth straight WAFL match when he went down with the injury, and now faces the painstaking task of trying to rebuild his body again

"He's realistic. He's probably been disappointed and kicked around enough that he's built a real resilience," Lyon said.

"He's had to build that, because there's been a lot of things written and said about Harley that have been inaccurate."

Lyon says out-of-favour forward Cam McCarthy is likely to replace Jesse Hogan for Saturday's clash with Carlton at Optus Stadium.

Hogan will miss several weeks with a right mid-foot sprain that isn't related to the navicular injury he suffered at Melbourne last year.

McCarthy booted five goals against North Melbourne in round one, but was dropped following goalless displays against the Bulldogs and Adelaide in round six and seven.

Although McCarthy has booted just six goals from five WAFL appearances since then, Lyon has liked what he's seen in recent weeks.

"He played really well on the weekend and over the last couple of weeks," Lyon said of McCarthy, who booted three goals against South Fremantle a fortnight ago.

"His work rate has been high and he's been working on his forward craft."

Adam Cerra is the favourite to replace Stephen Hill, who will miss three weeks with a hamstring injury.

Veteran Michael Walters is free to play after having his one-match ban for headbutting overturned by the AFL Tribunal.

Australian Associated Press