Port Adelaide's Willem Drew gets a handball away under pressure from Christian Petracca during round four, 2022. Picture: AFL Photos

PORT Adelaide's beleaguered defence has taken another hit on the eve of Thursday night's crucial encounter against reigning premier Melbourne, with Trent McKenzie ruled out of the side 60 minutes before the bounce due to a knee injury.

McKenzie has been replaced in the team by youngster Miles Bergman, while former North Melbourne wingman Trent Dumont will make his first senior appearance for his new club as its medical substitute.

McKenzie's absence further dents a Port Adelaide backline group that is already missing both Aliir Aliir and Sam Skinner to ankle injuries. Tom Clurey had already been rushed back into the team from knee surgery ahead of this week.

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Melbourne is unchanged from the side it named on Wednesday, with premiership defender Jake Lever confirmed for his first start of the season. He replaces Joel Smith, who has entered the AFL's health and safety protocols.

Toby Bedford will start as the Dees' medical substitute for the fourth straight week.

Port Adelaide is staring down the barrel of a nightmare 0-4 start to 2022 when it takes on reigning premier Melbourne tonight at Adelaide Oval from 7.10pm ACST.

A date with the in-form, undefeated Demons is the last thing the Power needs, with pressure piling on Ken Hinkley and his team as they try and break their season duck and give their fans something to cheer.

Port was considered a flag fancy in the summer, but now its finals hopes are on the line after shattering losses to Adelaide and Hawthorn in successive weeks.

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Injuries to key forward Charlie Dixon and key defender Aliir Aliir have hurt the Power, but they are also in need of a rise from some their highly touted youngsters.

22yo gun Connor Rozee has had a subdued start to the year, while Xavier Duursma was dropped last week and will not be back for tonight's clash.

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Veteran forward Robbie Gray is another star who won't be playing, with the club believing it is too soon for him to be named after coming out of the AFL's health and safety protocols only this morning. But experienced defender Tom Clurey is set to return from a knee injury to replace the injured Sam Skinner (the latter was withdrawn from last week's Showdown loss to Adelaide with an ankle problem).

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Meanwhile, Melbourne has flown through its own injury issues and is welcoming back flag hero and All-Australian defender Jake Lever for the game.

Lever returns from a plantar fascia injury for his first appearance of the season, replacing Joel Smith – who himself has entered the health and safety protocols – as the side's only change.

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Like Gray, Demons forward Ben Brown has come out of the health and safety protocols today, but the club is sticking with Sam Weideman after he booted a career-best four goals last week.

Port Adelaide v Melbourne at Adelaide Oval, 7.10pm ACST

LATE CHANGES
Port Adelaide: Trent McKenzie (knee) replaced in selected side by Miles Bergman
Melbourne: None

MEDICAL SUBS
Port Adelaide: Trent Dumont
Melbourne: Toby Bedford