HARLEY Bennell's chances of making his Fremantle debut this season have been cast into more doubt, with the injury-plagued Docker set to be sidelined for at least two months by his latest calf setback.

Bennell hurt his left calf at training last Tuesday and initial scans indicated only a minor tear, which was set to delay his return to main training by a week to 10 days.

He would then have needed about two weeks training with the full squad to be available for match selection. 

However, the 24-year-old experienced more discomfort late last week and follow-up scans have revealed the injury is more severe than first thought. 

Bennell, who missed the entire 2016 campaign due to problems with his right calf, is now facing 8-10 weeks before he is finally ready to resume playing. 

"Upon further assessment and following the latest scans, we were advised that the extent of the calf injury was more severe than the initial diagnosis last week," general manager of football operations Chris Bond said.

"It is disappointing for Harley and the club, particularly given that he was on the verge of a return to full training with the playing group and back out playing. 

"Given his outstanding attitude and approach to injury rehabilitation since he has been at Fremantle, Harley and the club are now planning for him to be available for selection within eight to 10 weeks." 

Fremantle coach Ross Lyon has previously stated Bennell's highly anticipated return would be via the WAFL at Peel Thunder.  

Bennell's latest setback continues a string of calf problems stretching back to his playing days at Gold Coast.

The damaging midfielder managed 81 appearances for the Suns and booted 92 goals before he was traded to Fremantle at the end of 2015.

But Bennell has only played one pre-season game for the Dockers last year and one match for Peel since his return to Western Australia.

He was sent to Germany for specialist treatment by renowned soft-tissue expert Hans-Wilhelm Müller-Wohlfahrt – the club doctor for Bayern Munich - in December after hurting his left calf at training. 

Müller-Wohlfahrt also earned his reputation for helping sprinter Usain Bolt and basketballer Kobe Bryant overcome their injury woes.  

Bennell's build towards playing again has been painstaking since his return from Germany.

He had progressed to high-end sprinting recently and was set to join in main training drills last week before his latest flare-up.