CAPTAIN Jack Ziebell headlines a trio of North Melbourne stars struck down by calf injuries that have caused interruptions to pre-season plans.
Ziebell joined defender Robbie Tarrant and forward Mason Wood on the sidelines during a one-hour match simulation at Arden Street on Friday.
After clocking heavy running loads prior to Christmas following minor knee surgery, Ziebell's latest setback restricted him to coaching duties during the physical hit-out.
Tarrant joined spearhead Ben Brown, who is on the comeback trail from post-season hip surgery, in a big running block away from the main group.
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While Brown completed much of training on Monday and Wednesday, Wood was confined to stationary ball work with draftee Joel Crocker.
Wood's calf concern comes after several years battling various knee and soft tissue injuries – he has never played a round one match in his five years at the Roos.
Jasper Pittard remains on a modified program, while others missing match practice included Sam Durdin (leg), Cam Zurhaar (ankle), Will Walker (knee) and Taylor Garner (soft tissue).
Midfielder Ben Jacobs continues to increase his running capacity after a frustrating 2018 campaign with lingering concussion-like symptoms.
On the track, recruits Aaron Hall and Jared Polec collected plenty of ball, while a noticeably leaner Paul Ahern also impressed.
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Ahern joined Todd Goldstein, Jed Anderson and Ben Cunnington in one centre square line-up, opposed to Tom Campbell, Hall, Shaun Higgins and Dom Tyson.
Anderson lasted close to half an hour before he was removed after a heavy tackle with Tom Wilkinson and was replaced by second-year midfielder Luke Davies-Uniacke.
Tyson, who hasn't missed a beat this summer after arm surgery ahead of last year's finals series, said he is flourishing in his return to a permanent inside midfield role.
Now at his third club, the former Demon and Giant has observed a number of differences in his first three months at Arden Street.
"You do notice there's good culture of past players here and you just get a feel for that Shinboner culture," Tyson said.
"You get a feel there's a good heritage here and past players are really proud of the club and what it stands for.
"The imagery around the walls and internal buildings are really good from that late 90s era which was when I was a six or seven-year-old, I remember watching North in those days."
And in terms of his teammates who have surprised him most: "I always thought Sam Wright was a pest when you used to play against him and he's a legend of a bloke.
"There's always a couple, it was Lynden Dunn, I used to think he was annoying and then you get there, he's actually a ripper bloke."
Meanwhile in defence, Ben McKay started in a back six resembling a first-choice unit alongside Luke McDonald, Scott Thompson, Sam Wright, Jamie Macmillan and Marley Williams.
After Majak Daw sustained serious injuries in a fall from the Bolte Bridge last month and with Thompson suspended for round one, McKay will have his eyes on early season selection.
Tyson said the playing group continued to rally around Daw.
"A lot of boys have been in constant contact and they're relaying a few things to the boys," he said.
"At the moment the spirits are good from what we're hearing and you're just confident the support's all there for him."
Coach Brad Scott remains on leave from the club after he was hands on prior to the Christmas leave.
