FREMANTLE ruckman Aaron Sandilands continues to progress in his recovery, as the Dockers' injury crisis appears to have eased slightly ahead of Saturday night's clash with Melbourne in Darwin.

Sandilands is still unavailable as he is working his way back from the multiple rib fractures and collapsed lung he suffered in round three.

He did not train with the Dockers' main group on Tuesday morning and still appears some way off being able to do full training and contact work.

But he did some straight-line running and light body-on-body ruck work with assistant coaches David Hale and Simon Eastaugh before running laps.

Match preview: Melbourne v Fremantle

Teammate Hayden Ballantyne said Sandilands had progressed well over the last few weeks. 

"He's been running around for a while so hopefully he comes back into the fray soon," Ballantyne said.

Coach Ross Lyon stated a fortnight ago that Sandilands would play again this season but could not put an exact date on his return, saying it would be at least "north of round 19".

The Dockers had 31 players participate in main training on Tuesday. That is an improvement on the 28 that were available for their match against Collingwood prior to the bye, although not all 31 are available to play.

Ruckman Jon Griffin looks set to return from a hamstring injury this week after training strongly.

Ethan Hughes (calf), Anthony Morabito (ankle), Alex Silvagni (calf), and Michael Apeness (collarbone) also trained, but only Hughes and Morabito are likely to be available this week and both are likely to play in the WAFL. 

Michael Barlow did a solid running session away from the main group after having surgery to repair a fractured finger he suffered in the loss to the Magpies.

Ballantyne said the Dockers' injury list was one of the longest he had seen in his time at the club.

"This, along with 2011, I think we were down to our last one or two players in 2011 as well," Ballantyne said.

"It's not great, but at the same time it opens up some opportunities for some young guys."

Ballantyne said the fit players should not concern themselves with the injury list when they play.

"My own philosophy is if you worry about that too much that's when you really get hurt," Ballantyne said.

"If you take a backwards step you get even more hurt.

"We'll still play exactly the same way, give great effort and go as hard as you can.

"Injuries happen, that's footy, it's a contact sport so you've just got to try and minimise it as best you can."

Veteran defender Michael Johnson appeared on the track with the rehab group after the main session was completed. The time frame on his return is still unknown but, like Sandilands, Lyon has stated Johnson would play again in 2016.