PORT Adelaide key defender Trent McKenzie will miss the rest of the home and away season after suffering a knee injury in Saturday night's loss to Geelong at GMHBA Stadium. 

The 31-year-old was substituted out of the game at GMHBA Stadium quarter-time after coming from the ground. 

Subsequent scans have revealed a posterior cruciate ligament injury that is expected to rule the Victorian out for at least the next month. 

McKenzie has been a revelation down back this season, playing 17 of 20 games but will be facing a race against the clock to be fit for the Power's first final. 

Port Adelaide was forced to make seven changes due to injury and illness ahead of the game in Geelong, while ruckman Scott Lycett has undergone surgery to repair the meniscus in his knee. 

Aliir Alirr and Lachie Jones didn't make the trip to Victoria after entering concussion protocols following the controversial incident in Showdown 54, but both could return for Sunday's twilight clash against Greater Western Sydney at Adelaide Oval. 

Jeremy Finlayson, Miles Bergman and Kane Farrell are all expected to be fit to face the Giants after missing the 12-point loss due to illness. Finlayson and Bergman were late outs on the day. 

Charlie Dixon didn't travel with the team after hurting his foot at training at Alberton last week and is no guarantee to return this weekend.

Ken Hinkley's side was soaring towards a top-two finish a month ago after winning 13 consecutive games, but have now been overtaken by Melbourne and Brisbane after dropping a fourth straight game in round 21. 

The Power remain 10 premiership points inside the top-four and face Fremantle at Optus Stadium and Richmond at Adelaide Oval after the fixture against Greater Western Sydney.