Carlton coach Brett Ratten is expecting Fremantle’s Ross Lyon to focus on defence on Friday, but the question for the Dockers is which stars to target.

Last week the Dockers scored an upset round-four AFL win over St Kilda at Etihad Stadium with Adam McPhee silencing Saints small forward Stephen Milne and Ryan Crowley shutting down midfielder Nick Dal Santo.

However Lyon face some tough choices at Patersons Stadium with dual Brownlow Medallist Chris Judd and last year’s best and fairest Marc Murphy spearheading Carlton’s midfield.

The Blues will welcome their 2011 leading goalkicker Andrew Walker back after overcoming a quadricep injury, as the Dockers consider sending McPhee to play on Eddie Betts.

Ratten is expecting Walker to add firepower to a forward line that managed only 11 goals in a loss to Essendon last week, including four from Betts.

“He (Walker) won’t play in the VFL,” Ratten said on Tuesday.

“He’ll come straight back in, and I’m glad he’s back because he’s bothered me.

“He’s in my office, sending me text messages, ‘I’m ready to go, pick me’.

“He’s ready to fire and play well.

“I wouldn’t like to be playing on him because they’re going to be do a few kilometres because he’s ready to be let off the leash.”

Sixth-placed Fremantle are the lowest-scoring team in the top 10, with 342 points for and 309 against for a percentage of 110.68.

Third-placed Essendon, fourth-placed Carlton and fifth-placed Adelaide have all conceded more than Fremantle.

“Their defensive set-ups and the way they do that, it makes it very hard for the opposition to score,” Ratten said.

“It was very Ross Lyon-like.

“Whether it was the team he was playing against last week, or whether it’s the new team he’s coaching now, it’s very similar set-ups.

“They’ll come for one of the boys. Crowley has been one who has got into a few over time.

“Chris or Marc will get a fair bit of support in regards to that.

“That’s up to them who they select. We expect they’ll run with somebody.”

The Blues have gone to school on Fremantle’s Aaron Sandilands who had 44 hitouts last week, including six to advantage and nine of which were sharked.

“We’ve had a look at it. We can see some of the patterns that Aaron does,” Ratten said.

The loss of tagger Andrew Carrazzo (fractured shoulder) means Ratten is considering promoting Aaron Joseph.

Dennis Armfield (knee) will return while Chris Yarran (toe), Ed Curnow (ankle) and Jeremy Laidler (knee) are only 50-50 chances to play.

Ratten said the Bombers out-muscled Carlton and the Dockers would pose a similar challenge.

“It will be on again physically,” he said.

Ratten is crossing his fingers he will return on Saturday in time to attend the birth of his third child.