Jonathon Patton's impending return will allow him to retake his place in Cameron's favoured three-pronged forward line, alongside Jeremy Cameron and Rory Lobb, but how Cameron configures the jigsaw around the big three looms as one of the coach's major selection dilemmas this week.

Johnson's knee flared up after the weekend's win over North Melbourne, during which he kicked his 500th AFL goal. The veteran forward was unable to train on Wednesday and Cameron won't play the 33-year-old against Port unless he can prove he's "100 per cent fit".

Greater Western Sydney will still look well served up forward despite Johnson's absence; Toby Greene and Devon Smith have managed 15 goals between them already this season.

Cameron said the form of the smaller forwards had been crucial for the club's strong start to the year.

"Most of the forward line's working pretty well at the moment," he said.

"Toby had a really good year last year and he's definitely put in the hard yards again this off season and this preseason. He's started the season well along with Dev; these sorts of guys are fantastic to have up there.

"At times Toby's got to play tall when we've only got two talls, Lobby might be in the ruck, [Shane Mumford] might be off and it's just myself. We can change it up quite a lot up there, which gives us good looks going forward."

Cameron has also been forced into a midfield dilemma in the lead up to the Port game after Ryan Griffen last weekend suffered an ankle syndesmosis injury that will cost him 10 weeks.

Matt Kennedy is in the frame after playing in the round one loss to the Adelaide Crows. Harrison Himmelberg and draftee Harry Perryman are also being considered.

Port Adelaide have their own headaches to manage after Paddy Ryder was rubbed out for Saturday's game by the match review panel, and fellow ruckman Matthew Lobbe was ruled out with a suspected hamstring injury.