Fremantle coach Ross Lyon says Harley Bennell will definitely play in the NAB Challenge but he will have to earn his spot in the opening rounds of the home and away season after missing a large chunk of the pre-season due to ongoing calf issues.

Bennell has not been named in the Fremantle Dockers' squad for their first NAB Challenge clash against Richmond on Friday at Rushton Park in Mandurah.

The 23-year-old has been in the Fremantle Dockers' rehab group since Christmas but Lyon said his return to the main group was imminent and he confirmed he would play a pre-season game.

"He'll definitely play," Lyon said on Wednesday. 

"He's going really well. He'll tell you he's ready to go now.

"He's had some reoccurring calf issues and with interest we read that (Chris) Yarran has at Richmond as well. So we decided to build his strength and build his run and we want him to be here for 5-10 years, not five weeks.

Two fresh faces for NAB Challenge

"We're not rushing him. We're building him really strongly. He's put on five kilos, his skinfolds are as low as they've ever been and he's in really good shape.

"We're excited for him to join the group, I think next week, and build from there. He's imminent really and getting a lot of work into him."

The Fremantle Dockers play their second NAB Challenge game against Adelaide in Mount Barker on Sunday February 28 before a final clash against Geelong at Domain Stadium on March 12. 

Lyon said Bennell would play in one of those games but he said he needed to perform well in order to confirm his spot in the line-up.

"He's still got to pick himself," Lyon said.

"Guys that have done a full pre-season have got a good jumpstart on him. So he'll have to reel that in. We just don't gift games here. He's got to earn it."