Colin Sylvia.

Colin Sylvia. Photo: Paul Kane

Last Friday, Fremantle skipper Matthew Pavlich pulled Colin Sylvia to the side and informed the former Demon that he wasn't far away from earning his Dockers debut.

It was music to Sylvia's ears after a tougher-than-expected start to his time in the west.

But Sylvia's hopes of a swift call-up now hang in the balance as he prepares to front the WAFL tribunal on Tuesday night on a serious rough conduct charge.

Sylvia is facing a four-match ban for his off-the-ball strike on Subiaco's Brett Mahoney.

The 157-game veteran has endured a topsy-turvy time since arriving at Fremantle as a free agent at the end of last year.

Sylvia struggled for form during the pre-season, with Fremantle's relentless work ethic catching him on the hop after spending 10 years at struggling Melbourne.

The 28-year-old had made some significant strides forward in recent weeks but his moment of madness over the weekend may undo all that good work.

"It's just disappointing to have a setback like that on the weekend," Pavlich said.

"He took some time to understand exactly how we do it here and what we stand for, but certainly he's bought into that and is going quite well.

"We felt he had developed and grown."

Fremantle forward Chris Mayne (ankle) remains a chance to return for Saturday's clash with Sydney at the SCG while midfielder David Mundy (concussion) is another player who will have to prove his fitness.

The return of star midfielder Nat Fyfe from suspension comes at a perfect time for a Dockers outfit still missing the class of Michael Barlow (knee), Michael Walters (ankle) and Garrick Ibbotson (shoulder).

Walters will find out this week whether he requires surgery after dislocating tendons in his left ankle in the round three loss to Hawthorn.

Sydney sit in 13th spot after managing just one win from the opening four rounds.

Star recruit Lance Franklin has failed to fire thus far but Pavlich said it would be wrong to write off the Swans.

"Clearly the results haven't gone their way but what we do know is they've got fantastic leaders and really talented players," Pavlich said.

"We're not going to fall for the story that Sydney aren't going that well."

AAP