FREMANTLE coach Justin Longmuir hopes a rare night training session will give his players the necessary boost to break out of their mid-season funk.

The Dockers' finals hopes are hanging by a thread after suffering shock losses to Richmond and Greater Western Sydney following the bye.

Last weekend's 70-point defeat to GWS was of particular concern, with Fremantle simply uncompetitive in most key aspects of the game.

The Dockers lost the contested possession battle 140-116, clearances 39-29, centre clearances 16-6 and the inside 50s count 68-44 in what became Fremantle's biggest loss under Longmuir.

The Dockers have also finished 16 of their past 17 first quarters trailing on the scoreboard – a worrying trend for which Longmuir is yet to find a fix.

Fremantle usually undertakes its main training on a Wednesday morning at its Cockburn base but this week has instead opted for a night session at Optus Stadium.

Longmuir hopes the schedule tweak will have a positive effect leading into Saturday night's crunch clash with Essendon in Perth.

"We just thought it was a necessary change up to add a bit of a different vibe to the week," Longmuir told reporters on Thursday.

"We don't train at night a lot, and when we do we get a good energy lift and the players enjoy it.

"It has a few benefits."

Fremantle will be boosted by the return of ruckman Sean Darcy (hamstring) and goalsneak Michael Frederick (ankle) against the Bombers.

But wingman James Aish, who was recovering well from concussion, has been ruled out with a back problem.

"It came out of the blue," Longmuir said of Aish's injury.

"It's not stress related. It's something you can get on top of pretty quickly.

"It's going to cost him this week."

Fremantle (6-7) sits 13th on the ladder, and can ill afford to lose to the sixth-placed Bombers (8-5) if it wants to stay in the finals hunt.

Longmuir isn't putting too much focus on his team's precarious position.

"It's just crucial that we get back to playing our best footy, and the rest will look after itself," he said.

"We know our best is good enough, and that last week was unacceptable."

Essendon will be bolstered by the return of gun midfielder Darcy Parish but ruckman Sam Draper is expected to be ruled out with a lingering hip issue.

Parish will return after missing five games with a calf injury.