HARLEY Bennell's long-awaited debut in Fremantle colours will once again be pushed back after coach Ross Lyon ruled the midfielder out of round one.

Fremantle will face Geelong on Sunday, March 26 at Domain Stadium in its season opener. The Dockers are coming off a dismal season which saw them finish 16th last year after winning the minor premiership in 2015.

Answering questions on a Facebook Q&A for AFL.com.au, Lyon said Bennell would hopefully play early in the year. 

"He won't be available for round one but his rehab is progressing well, particularly post-Germany. We expect to see him, if all goes to plan, in the early rounds," the coach said. 

Bennell went to Germany last December to see Dr Hans-Wilhelm Muller-Wohlfarht, a specialist who works with the best athletes in the world (including Usain Bolt), to overcome the calf issues that have plagued him in his time at Fremantle and forced the ex-Sun to miss all of 2016.

The Dockers expected at the time of Bennell's setback last November that he would be ready to go for round one.

"I think it’s a slight strain from the information I've been given, we still think he'll be available for round one," Fremantle list manager Brad Lloyd said on AFL.com.au's NAB AFL Draft Countdown Show at the time.

Lyon told AFL.com.au on Thursday Bennell's recent left calf problems were far less serious than the "90 per cent" right calf tear that sidelined him last season.

"He's got a program mapped out but you've got hit KPIs. He's been hitting them and we've taken a different program … this was much more minor than the tear which kept him out last year," Lyon said.

"But because it was on the other leg we've taken quite a conservative approach.

"Harley is not a 12-month project. He's still a young man. He has high-end capabilities and he trains really hard and it's really important that we get this one right as best we can for Harley's sake.

"When players do everything they're asked to do and they break down we feel like we've let them down, not that they've let us down."