Ziebell, 24, trained away from the Kangaroos' main group at Arden Street on Thursday afternoon, and will be named in the side's preliminary 25-man squad on Thursday night as he hopes to play eight days after sustaining a bruised lung against Port Adelaide.

Roos coach Brad Scott confirmed his enforcer was in the mix. "The doctors and the sports science guys have got some pretty specific tests around lung function," Scott said before training. "He's actually feeling terrific, he feels like he can play today but we've got to make sure his lung function's right, there's no risk."

Scott quashed any suggestion the test would involve any potentially bruising contact work. He said things have changed since the days when his former teammate Nigel Lappin was brutally worked over in the lead-up to the 2003 grand final.

"We're not interested – if there is a problem – in making it worse." Scott added that a clear decision would present itself from the results. "It's going to be really cut and dry we think."

With Geelong having been beaten at home already this season by Fremantle – and almost knocked off again at Simonds Stadium by Gold Coast last Sunday – bookmakers have installed North as favourites to record their first victory at the venue in eight years. With champion midfielder Jimmy Bartel out due to a knee injury and spearhead Tom Hawkins in doubt after the death of his mother, this is seemingly North's chance to break their run of outs at the ground.

But Scott would not entertain the thought of his 1-2 side facing anything but a stern challenge.

"I wouldn't think that playing Geelong this week we'd have any more confidence than any other week. That win against Gold Coast was full of merit, and it was full of courage, and it was full of character.

"I think that Geelong, the discussions around their death, have been premature. They're still a very formidable side with formidable players. They've been a team in transition for quite a while. I admire they way they've been able to lose so many greats of their club and transition some young guys through. They're like a lot of teams, they're in a state of flux. I think the talent they've brought in has been pretty significant."

Plaudits have flowed thick and fast this week for Cats skipper Joel Selwood after his inspirational 38-possession showing against the Suns. Many have questioned where Geelong would be without their captain.

But the North coach scoffed at the notion that stopping Selwood was akin to stopping the Cats. "Yeah Harry Taylor might disagree with that. I reckon Tom Hawkins disagrees, Mitch Clark definitely would. Cam Guthrie as well. I think that's disrespectful to the rest of the Geelong side. He's a great of our competition, but there'll be 21 other very good Geelong players out there."

Scott added that despite the significance of the club's semi-final victory last year against the Cats, he would not draw on that game ahead of this Sunday's encounter, contending that both teams had changed substantially since that Friday night September thriller.

Scott said he thought defender Jamie McMillan "would be fine" to play this weekend, while onballer Daniel Wells would have "a lighter session" before being tested closer to the clash at Simonds Stadium. Both are recovering from Achilles injuries, and Scott flagged the need for the side to be careful.

"You've mentioned three guys there so we've got to make sure that they're right. We're not going to take guys in who are not quite right and take a risk."