NORTH Melbourne defender Robbie Tarrant will have surgery on his right shoulder to repair a damaged AC joint sustained during an intraclub match on Wednesday.
However, the club expects the key big man to be fit for round one despite the significant interruption to his preparation.
Tarrant's injury will mean another change to squads for next Friday's realeastate.com.au AFLX tournament, with the defender picked in Patrick Dangerfield's Bolts team.
He joins Hawthorn's Chad Wingard, Port Adelaide's Robbie Gray, and Docker Joel Hamling on the sidelines for the tournament.
Tarrant, 29, suffered the injury when he was propelled forward in a tackle during the match practice at Arden St.
He had only recently returned to full training after a calf injury.
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"Fortunately Robbie was able to complete a decent block of work fitness-wise which will hold him in good stead," North football manager Cameron Joyce said.
"All we can do now is ensure that he's fit and firing in time for the start of the season.
"He'll be operated on tomorrow and he'll waste no time with his recovery and rehabilitation."
Young forward Nick Larkey was the only other injury concern of note, sitting out the second half after copping a heavy head knock in a marking contest with Shaun Atley.
Meanwhile, Jared Polec concedes there will be "a little bit of expectation" on him in his first season at North Melbourne, but the wingman looks set to justify the Kangaroos' faith after a standout performance in an intraclub practice game on Wednesday.
Polec crossed to North from Port Adelaide in last year's period on a five-year deal understood to be worth about $3.5 million.
The 26-year-old is coming off a career-best 2018 season in which he averaged 25.1 possessions, 16.4 kicks (ninth in the AFL) and four inside 50s a game.
He carried that form into Wednesday's 'City v Country' match at Arden St, showcasing the outside run and pinpoint left foot that prompted the Roos to invest so heavily in him.
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It was a promising start to his time at his third AFL club, but the former Lion and Power player knows he will be expected to deliver when the home and away season begins.
"I've done the move before, so I'm pretty used to how to go about it and what to do," Polec told reporters on Wednesday.
"I guess there is a little bit of expectation, but I've just got to play my role and it will keep me in the side."
Polec was one of four recruits North added in a busy 2018 trade period, with Demon Dom Tyson, Sun Aaron Hall and Polec's Port teammate Jasper Pittard also crossing to Arden St.
However, after a summer heavy on match simulation Polec is confident he and the other new Roos are forging a solid on-field understanding with their North teammates.
"I think we're all starting to jell now. It's starting to get at the business time and the more games we get in the more we jell, and I think we're pretty close," he says.
Tyson and Hall also impressed in Wednesday's game, Tyson with his prolific clearance work and Hall with his run and delivery inside forward 50.
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Last year's No.8 draft pick, Tarryn Thomas, showed promising signs too. His skill was obvious with a clever knock-on that lead to a Cameron Zurhaar goal and a superbly judged left-to-right major of his own, while his courage shone through when he recovered from a heavy collision with Hall to make a late spoil on Ben Cunnington on the wing.
Father-son recruit Bailey Scott also showed glimpses of his elite running, while experienced Roos Cunnington, Luke McDonald and Tarrant dominated for their respective teams.
Veteran defender Sam Wright sat out the second half after dislocating a finger.
Pittard and forward Mason Wood (calf injuries) did not play in Wednesday's game, while Taylor Garner, Ben Jacobs, Paul Ahern (load management), Todd Goldstein and Shaun Higgins (personal leave) were also missing.