PORT Adelaide defender Darcy Byrne-Jones has been axed for Saturday's clash with Carlton at the MCG for arriving late to a training session.

In-form backman Tom Jonas has also been ruled out with a hamstring injury, while former Melbourne co-captain Jack Trengove will debut for the Power and Jack Hombsch returns to the side.

Power coach Ken Hinkley said it was the first time Byrne-Jones had been late to a training session when he arrived late on Monday.

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The 23-year-old's demotion snaps a streak of 56 consecutive games since making his debut in round three, 2016 against Essendon.

"Without going into all the details, that (his alarm not going off) is basically what happened," Hinkley said.

"Our leadership group and us as coaches, we're building a really strong culture around what's expected.

"Darcy understands that, he's disappointed, but that's just the way it goes.

"Darcy is such a professional in everything he does, he's been such a good player for us, so we'll certainly miss him, but there's a level you have to commit to."

The Power's decision to drop Byrne-Jones opens the door for Trengove to play his first game for the club since joining as a delisted free agent at the end of last season.

The second overall pick at the 2009 NAB AFL Draft, Trengove had a horror run of foot injuries at Melbourne, but has banged down the door with impressive performances for Port Adelaide in the SANFL this year.

It will be just the 26-year-old's eighth AFL game since 2013 after getting close as a travelling emergency several times this season.

"As you can imagine, he was fairly excited," Hinkley said.

"He's worked really hard and he's busting for a game.

"He's done more miles than most of us – he's been to China, he's been to Perth, he's been to Tasmania – he's just not played, so now he gets to play."

Jonas has carried a hamstring injury for a few weeks, and was outstanding in the Power's 10-point win against Melbourne last Friday night.

"He's been able to get through games, but he hasn't quite felt 100 per cent," Hinkley said.

"Even at training this morning, he felt the same sort of way.

"We just can't take the risk and if we play him this week and he ends up missing three, four or five weeks, we'd be kicking ourselves."

The Power have won five of their past six games, but aren't underestimating the bottom-placed Blues.

"Their form has been really solid without winning over the last month," Hinkley said.

"Collingwood, Sydney and Geelong, so they've played three really good teams and really pushed them right to the end.

"We've got to be at our best."