The Dockers improved their record to 3-2 with a fighting 12-point AFL win over the Adelaide Crows at Adelaide Oval last week.

Fremantle are a perfect 2-0 at home so far this season, beating GWS by 31 points in round two and backing it up with a 15-point win over Hawthorn in round four.

The Dockers gave up an average of just 68.5 points per game over those two matches, but Longmuir wasn't satisfied.

"We've still got to defend Optus a little bit better," Longmuir said.

"We defended really well against Adelaide last week, but we haven't defended Optus as well as we would have liked at times. That's our challenge this week."

The Dockers now have a run of three straight games in Perth, starting with Saturday night's clash with North Melbourne.

The Kangaroos sit dead last with a 0-5 record and a paltry percentage of 45.4 per cent.

But North Melbourne have shown more fight over the past two weeks in losses to Adelaide and Geelong.

Longmuir won't be taking the wooden spoon favourites lightly on Saturday night.

"North Melbourne have been improving week in week out," Longmuir said.

"It's not easy to go down to Geelong and be ultra competitive.

"They pushed Geelong all the way. They were in front of Adelaide at three-quarter time.

"We've got respect for what they're trying to do. We understand they're improving every week and we're ready for it."

The Kangaroos welcome back Luke Davies-Uniacke (calf) and Cam Zurhaar (concussion), while Curtis Taylor and Connor Menadue are also recalled.

Aaron Hall (concussion), Kyron Hayden (hamstring), Charlie Lazzaro (managed), and Bailey Scott (omitted) go out of the side.

The Dockers lost midfielder Adam Cerra to an ankle injury, and have replaced him with goalsneak Mitch Crowden in their only change to the 22.

North Melbourne coach David Noble suggested Ben McKay was the most likely candidate to match up on Fremantle's Matthew Taberner, who kicked four goals against Adelaide last week.

"He has been really solid ... he has been in terrific form," Noble said of McKay, who is fresh from keeping reigning Coleman Medallist Tom Hawkins to one goal.

Noble also suggested the North coaching staff would have their hands full trying to negate the influence of Fremantle's impressive midfield.

"It's a combination isn't it? (Nat) Fyfe's dangerous, (David) Mundy is in great form and then you've got (Andrew) Brayshaw who's still learning his craft so we probably need to do a bit of work on all three," he said.

Australian Associated Press