PORT Adelaide coach Matthew Primus says he's taking a cautious approach with injured players after watching a wounded Essendon capitulate in the second half against Collingwood at the MCG last weekend.

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The undermanned Bombers, who lost Brent Prismall (knee) and Travis Colyer (leg) to serious injuries in the first quarter of the match and were forced to field several 'sore' players, were outscored three goals-to-16 by the fast-finishing Magpies after half-time.

The Power were also hit hard by injury last round, losing forward Jay Schulz (foot/back) and defenders Tom Logan (foot) and Jackson Trengove (knee) during their 32-point loss to Adelaide.

Schulz and Logan were both ruled out of the clash with Collingwood at AAMI Stadium on Saturday night earlier in the week, while Trengove was cleared of structural damage and is expected to play.

Midfielder Matt Thomas and defender Troy Chaplin were originally included in the team to play the Pies, but withdrew on Friday because of respective knee and foot complaints.

They haves been replaced by Matt Broadbent and Ben Jacobs.

Final Teams: Power vs Pies

Primus said he didn't want to risk taking injured players into the game.

"We just don't think Troy and Matt are going to be fit enough to get through a full game of footy," he said on Friday.

"We saw what happened to Essendon last week with two men down, so we have to pick a team that's capable of staying on the team for four quarters.

"Troy could've got through if we injected it [his foot], but then he would miss all of next week's training probably and we'd have to do the same again [next game].

"Matty had a sore patella. He tried to run this morning too and once again it was touch and go, but we've probably got a couple of other sore guys in the team so the more we have in there the more risk we have of being a few men down in the game."

Primus conceded his team would be "a little vulnerable" in defence, without Chaplin and injured full-back Alipate Carlile (hip), but said it would be another good test for Jackson Trengove, who will have the job on Travis Cloke.

Saturday night's clash will pit the bottom-placed Power against the ladder leaders .

The Magpies have won their past four games by an average margin of 66 points, while the Power have lost seven straight games.

Primus said his team was focused on putting in a competitive performance.

"We don't want to have that [a blow out] to happen to us," he said.

"Results can [blow out] a bit towards the end of the season depending on how some teams are going, but we want to fight this season right out until our last game in round 24.

"We'll be looking forward to trying to beat Collingwood and making it as a competitive game as we can."

The game against Collingwood will be retiring veteran Chad Cornes' last, and probably midfielder Hamish Hartlett's last for the season.

Hartlett requires a shoulder reconstruction, and is tipped to have the surgery next week, allowing him to be ready for the start of pre-season training.

The club also needs to start preparing its coaching group for next season.

Primus denied he'd already spoken to sacked Melbourne coach and former Power premiership assistant coach Dean Bailey, but said he planned to.

Katrina Gill covers Port Adelaide news for afl.com.au. Follow her on Twitter: @AFL_KatrinaGill