TRAINING at Optus Stadium before home games impacted Fremantle's leg weights program and could have contributed to a spate of hamstring issues, coach Ross Lyon says.

A review into the Dockers' injury toll is underway, with the club investigating reasons behind a number of soft-tissue problems in the second half of the season.

Losing superstar skipper Nat Fyfe in the first game after the round 14 bye was the major blow, but the likes of Joel Hamling (calf), Aaron Sandilands (calf) and Stephen Hill (quad) have also battled complaints.

Fyfe missed six matches after pinging his hamstring against Brisbane, while Sandilands hasn't been seen again after straining a calf during the warm-up of the same game.

Hamling has been named to return against Collingwood on Saturday after three weeks out, but Hill has withdrawn and will sit out a third-straight game.

The 28-year-old has missed nine matches this year across five stints on the sidelines battling repeat quad complaints.

Emerging defender Luke Ryan (hamstring, round 21), big man Michael Apeness (hamstring tendon, round 17) and possibly Michael Walters (round 21) are among others struck down recently.

Walters was initially ruled out for the season with a hamstring strain but then played last round in Geelong after it was revealed to be a lower buttock issue.

However, the star forward has been ruled out of the Pies clash due to an unspecified injury.

"Post the bye, for whatever reason, there's been a higher incidence of some soft-tissue and, I think, predominantly hamstring (injuries)," Lyon said.

"It can be as simple as training up here (at Optus Stadium), so the quality of our weights on our second session on our legs hasn't been the same, so there's been a cost to coming up here."

Freo has been ordinary since the bye, winning two games and losing six by an average of 65 points, and injury woes haven't helped the cause.

Lyon backed high performance manager Jason Weber to put a finger on the issue.

"Jason Weber coached the Wallabies (in strength and conditioning), there's no more qualified person in Australia and he's been with us eight years," Lyon said.

"Without being perfect, I'm sure that they'll drill in and present it up.

"I've got high trust in Jason Weber and his team."

Small forwards Brady Grey and Sam Switkowski have had long-term hamstring worries, but their setbacks were earlier in the season.

It has been a frustrating year on the injury front, with Harley Bennell (calf), Griffin Logue (foot) and retired backman Lee Spurr (knee) failing to play a senior game.

Doig medallist Bradley Hill also missed three months with a knee injury originally expected to keep him sidelined for a week.

Connor Blakely (knee), Sean Darcy (knee), Matt Taberner (foot) and Hugh Dixon (ankle, hamstring) also had lengthy injury concerns.

FREMANTLE SOFT-TISSUE INJURIES

Hamstring – Michael Apeness, Hugh Dixon, Nat Fyfe, Brady Grey, Tom North, Luke Ryan, Cam Sutcliffe, Sam Switkowski, Michael Walters (possible)

Calf – Harley Bennell, Joel Hamling, Aaron Sandilands

Quad – Stephen Hill