NORTH Melbourne has ruled out Lachlan Hansen (hip), Leigh Adams (concussion) and Jamie Macmillan (hamstring) from this Friday night's preliminary final against the Sydney Swans at ANZ Stadium.

North coach Brad Scott told reporters on Thursday that the injured trio would not play against the Swans, but said key defender Joel Tippett was in the Roos' extended squad and could play given the Swans' wealth of tall forward options led by Lance Franklin and Tippett's elder brother Kurt.

Macmillan was the only one of the injured trio who played in last week's semi-final win over Geelong, meaning North will have at least one change to its team this Friday night.

Scott said North was hopeful Adams and Hansen would be available for selection if North reached the Grand Final.

"'Patch' (Adams) won't play, he's close, but he's just not quite right. He saw a specialist whose advice was to err on the side of caution and give him one more week," Scott said.

"But the good news is he's able to train fully and get a lot of work under his belt and should be available for selection next week if required.

"Lachy trained on Wednesday but not quite well enough, so again he was very close and he's an important part of our back half.

"We'll keep training him and rehabbing him and hopefully he'll again be available next week if we're there."

Scott said Tippett, who has not played a senior game since he tore a pectoral muscle against Geelong in round 10, would fly up to Sydney on Thursday afternoon with the North team.

The North coach said that when the Roos finalised their 22 they would have to seriously consider adding height to their defence, given the Swans could use Franklin, Kurt Tippett, Sam Reid, Adam Goodes and Mike Pyke in attack.

"I think we have to look at that because clearly with the weaponry they've got in their forward half with their talls it's important to have all options available," Scott said.

"Fortunately, we've got enough players to cover that even with Hansen out."

Scott Thompson held Franklin goalless the last time North and the Swans met, in round four this year on a wet day at the SCG.

The Roos coach said North was likely to rotate a variety of defenders on Franklin, but its ability to limit his influence would be largely dependent on cutting his supply up the ground.

Scott said having Brent Harvey available for the Swans clash was a bonus, after the 36-year-old had a one-match suspension overturned at the Tribunal on Tuesday night.

But Scott said his players now believed they could win big games without the star veteran, especially since they had gone undefeated during Harvey's three-match suspension following round 21, which included the elimination final win over Essendon.

"They probably may not have believed it before, but they certainly believe it now, so [Harvey's availability] is an added bonus for us," Scott said.

"But the players have got real confidence that we could have got the job done without him as well."

Scott said he had detected no signs that his players would head into Friday night's clash already content with their season after finals wins over Essendon and Geelong.

"I've been really pleased with the attitude of our players that we've got a job still to do," Scott said.

"We're certainly not satisfied with what we've achieved so far and we're going to put our best foot forward on Friday night.

"We've got supreme confidence that if we bring our best and limit what Sydney are good at then we can prevail.

"We're looking forward, we're not looking back and resting on our laurels."