GREATER Western Sydney is expected to welcome back star forward Toby Greene for Saturday's clash with Fremantle, but ruckman Rory Lobb remains in doubt after failing to train on Wednesday.  

Greene has missed the past two games with hamstring tightness but moved well at the Giants' main training session. He's certain to face the Dockers if he pulls up well on Thursday.  

Lobb injured his left knee in the second quarter of last week's loss to Sydney at the SCG and, while he returned to the field and played out the game, he was limited to playing as a permanent forward with the knee heavily strapped.  

If the West Australian doesn't get up for the round four match in Canberra, Dawson Simpson will take his place for the match-up on Fremantle veteran Aaron Sandilands.  

GWS coach Leon Cameron hasn't completely ruled out Lobb's chances, despite the ruckman's struggles during week.  

"Considering the way he went down was pretty nasty, we played him at full forward for the remainder of the game (against Sydney)," he said.  

"We didn't want to risk that jumping contact, and him landing on it over and over again.  

"But he's pulled up really well, there's clearly some bone bruising there and a few other minor things.  

"We'll take towards the end of the week (before deciding on his availability), he's either right by Thursday, or Friday morning, or he's not.  

"He is a genuine chance but if he's not 100 per cent or close to 100 per cent, there's no way we can risk him against a guy like Sandilands who is in great form."  

Cameron said he has full faith that Simpson, if he is called upon, will be able to match it with Fremantle's premier big man.  

"Is it a challenge? Absolutely, because you're talking about one of the best ruckman of the last 10 to 12 years," he said.  

"He's great at his craft, he gives great service to his midfielders, and he can go forward and mark the ball.  

"We're under no illusions that the midfield battle is going to be huge and the ruck battle will be part of that."  

While the loss of Lobb would be a blow for the Giants, Greene would be a massive inclusion.  

The 2016 club champion and All Australian had a late start to the pre-season thanks to a broken toe, but he starred against the Western Bulldogs in round one, kicking four goals from 10 marks and 25 possessions.  

Cameron said Greene was close to playing against the Swans last week, but the club decided against risking one of its most important players.  

"There's times he'll be a bit rusty but hopefully we can get him into some rhythm and there's no more setbacks from here," he said.  

"It's always a challenge when players have an interrupted pre-season (and) seeing how their season pans out.  

"But he's trained well, and all indicators are that he'll be right for Saturday."  

Veteran Ryan Griffen (ankle) looms as another possible inclusion against the Dockers after he got through another NEAFL match last week.  

Cameron said the decision on Griffen, who hasn't played a senior game since round three last season, will be a tough one for his match committee.  

"We realise Fremantle's ability to run and the ability of their small forwards to cover ground is enormous," he said.  

"We've got to take that into consideration as well, but the good thing is that he's right in the firing line, and we feel as though if he doesn't play this week, it will be next week."