PORT Adelaide spearhead Charlie Dixon is facing another month on the sidelines after suffering a setback at training last week. 

And in another blow to the winless Power, five-time Showdown medallist Robbie Gray has been ruled out of Friday night's clash against Adelaide due to health and safety protocols, while recruit Jeremy Finlayson has been dropped.

Sam Mayes and Jed McEntee will be among the inclusions for the Showdown.

Dixon, who had ankle surgery on the eve of the season, was pushing to return but suffered bone bruising on the inside of his ankle following an incident at training. 

MEDICAL ROOM Check out the full injury list

The club says it is unrelated to his surgery, but the 31-year-old will still be sidelined for a month. 

"It's a big concern," Port coach Ken Hinkley said on Thursday.

"Charlie ... hasn't missed a game in two years (prior), he's a critical piece of our team as is Aliir (Aliir) down the other end.

"But we need to step up. We need to fill the boots of someone who is not there."

Gray is expected to play in next week's clash against Melbourne after clearing the AFL's Health and Safety protocols. 

The Power are also missing gun defender Aliir Aliir (ankle) and Orazio Fantasia (knee), while Trent McKenzie (ankle) is in doubt for this week.

Port Adelaide is still searching for its first win after losses to Brisbane and Hawthorn to begin the season. 

The Crows are also winless in what is shaping as an intriguing Showdown on Friday night.

"We deserve the pressure, we embrace the pressure," Hinkley said.

"Pressure is good as far as we expect to be a good side ... our expectation as a football club is we are a strong and high performing team.

"And with that comes expectation and pressure, that is part of the game.

"It's not something that we get spooked by, it's something that we understand and appreciate."