FREMANTLE coach Ross Lyon says he still doesn't know why Ryan Crowley ignored club protocols to obtain a painkiller from an outside source.

Crowley is facing a suspension of up to two years after failing a doping last July, with the AFL's anti-doping tribunal to decide his fate in the near future.

Fremantle believes the banned substance was contained in a painkiller Crowley took in the lead-up to the club's round-17 win over GWS last year.

The Dockers are adamant they did not supply the painkiller in question.

Lyon found out about the positive test last September, but he said the circumstances surrounding the acquisition of the painkiller were none of his business.

"I still haven't sat down and said to Ryan, 'What occurred?' Let's be really clear on that, because it's none of my business and I can't do anything about it," Lyon said on Friday.

"All I say (to Crowley) is we're supportive. We'll support you until we can't as a club, and I get on with business."

Lyon said Crowley was doing his best to keep his spirits high.

"It's very hard to sit on significant matters that affect your professional life for a long period of time," Lyon said.

"There's an element of relief (that it's now public).

"He seems pretty bubbly, buying into team meetings."

Fremantle crashed out of last year's finals series in straight sets, but Lyon said Crowley's positive test had nothing to do with that.

The uncertainty surrounding Crowley's future is an unwanted distraction for the Dockers heading into their season opener against Port Adelaide in Perth on April 5.

Crowley addressed the player group earlier this week, and Lyon is urging the team to put the matter out of their mind.

"I suppose the players don't want it to be a distraction," Lyon said.

"I just spoke to the player group ... if Ryan cares to engage you and take you offside and have a talk, he can do that.

"We're a mature group. Everyone's been through bits and pieces before, including myself."

Lyon said Clancee Pearce and Nick Suban were players being groomed to take over the tagging role, while Matt de Boer was another option.

Pearce played on Kieren Jack in last week's loss to the Sydney Swans, and he's a chance to be given another shutdown role in Sunday's practice match against West Coast at Domain Stadium.

Fremantle remains hopeful Hayden Ballantyne (calf) will be fit for the season opener, while Tendai Mzungu (hamstring), Paul Duffield (ribs), and Michael Barlow (ankle) are expected to recover in time.