GREATER Western Sydney co-captain Phil Davis looks likely to resume his position as the anchor of his side's defence for Sunday's crunch clash with Melbourne at the MCG.

Davis, one of the Giants' most important stars playing a key role in the back half, was reduced to playing as a decoy forward in last week's loss to Sydney at Spotless Stadium after suffering a corked hip in an accidental collision with teammate Rory Lobb in the second quarter. 

The 27-year-old had been on top in his battle with superstar Swan Lance Franklin until he went down, and his presence in defence was sorely missed in the second half. 

GWS coach Leon Cameron said on Friday that he expected Davis to be ready to face the Demons, along with star midfielder Josh Kelly (concussion) and Sam Reid (hamstring), who both missed the derby.

"Phil got a cork in his hip and one in his buttock on one side, and another one on the other side, so that really restricted him, and unfortunately he copped it in the same spot again in the last quarter," he said. 

"We think he's going to get there, he had a pretty good day on Thursday, and he's pulled up pretty well. 

"We know how vital he is to us and he's progressing in the right manner, and it's good that our captain can constantly get up and play under duress."

The Giants resisted the temptation to pick attacking defender Zac Williams despite his outstanding return to footy in the NEAFL last week, when he gathered 30 possessions against the Swans.

Cameron said the 23-year-old was the subject of much debate at this week's selection meeting but denied his non-selection has reduced his chances of being selected for senior footy during the finals.

"I'll have no hesitation in bringing him in," he said. 

"He'll play (reserves) again this week and then gets another couple of weeks of good training in.

"Six months is a long time out of footy and as much as I'd love to see him running around at the MCG, it's a more conservative approach.

"If it had of been two or three months it would have been a no-brainer.

"But you've got to weigh up the risk of throwing him into a pressure game, it's going to be like a final, so it's a big ask."

While the injuries to Davis and veteran Ryan Griffen (hamstring) were no doubt a factor, the Giants were poor in the second half against the Swans and were especially down when the game was up for grabs in the last term. 

The Swans dominated the centre clearances (6-1) and inside 50s (20-3) and booted 6.5 to 1.3 to turn a 12-point three-quarter time deficit into an important 20-point victory.

Midfield stars Dylan Shiel (four possessions), Callan Ward (four) and Stephen Coniglio (two) had little impact when Sydney ran over the top of the home side, and Cameron said if his prime movers fall away again, the result will be the same on Sunday. 

The winner of the match will earn themselves a home elimination final. 

"We know the ramifications of this game, so we just need to play the full 120 minutes, like we had done prior to the weekend for a couple of months," he said. 

"We clearly let ourselves down against the Swans, and Melbourne have been a fantastic side all year and have been in a lot of games.

"That’s the sign of a very good team.

"The Demons are coming, they want a home final and we want a hone final, so the finals have started early."