ROSS Lyon says Fremantle has already moved on from losing experienced defender Michael Johnson for the remainder of the finals series.

Johnson, an All Australian last year, requires back surgery this week and has been ruled out from taking any part in the Dockers’ September campaign.

Lyon said Alex Silvagni is certain to return to tackle the Sydney Swans’ powerful forward line, while tall utility Anthony Morabito could be a dark horse to play in defence.

"Mentally I've moved on," Lyon said of the Johnson injury on Tuesday.

"It's not the ideal scenario for us, but it's not something we're dwelling on.

"Alex Silvagni will definitely come in. Alex Pearce has had a really good year (for a) young player. It'd be a big thing to throw to him (in) but he's capable.

“Tanner Smith has played senior football and Morabito is a bit of a wildcard… then do you put a Zac Clarke back there or a (Chris) Mayne and bring in another tall, (Jon) Griffin and (Jack) Hannath, or go a bit smaller because it's going to rain?

"We'll come up with a solution we're comfortable with."
Luke McPharlin is highly unlikely to return from his calf problem this week to face the Swans, but Lyon said he was planning for his veteran defender to play some part in this finals series.
Star midfielder Nat Fyfe returns from his two-week suspension for Saturday's qualifying final and Lyon said the club’s reigning best and fairest winner was raring to go.
"He will be fresh, he won't be sore," Lyon said.
"He plays a very physical game. We've been able to put a lot of work into him. He has been in my office two or three times over that period just talking about how keen he is.
"He has set himself for finals football and we're thrilled to have him back."
One concern for Fremantle this week is that the club has very little experience at ANZ Stadium. The Dockers have only played there once, in the 2006 preliminary final, and of the players available this week only Matthew Pavlich, Aaron Sandilands, David Mundy and Ryan Crowley played in that game.
Zac Dawson has also played there for St Kilda in the 2011 elimination final.
The Dockers won't train at the venue before the match as is their custom but they have marked their training venue Fremantle Oval to the dimensions of ANZ Stadium to prepare this week.
"It's 118m in width, so we'll get to practise that. Other than that - big, small, medium, we don't care,” Lyon said.
"We never train interstate."
Lyon said he was not concerned about the standard of the surface at ANZ Stadium.
"Not one iota," Lyon said.
"I know the AFL will provide a safe working environment for our players. I know it will be playable."