Aaron Sandilands will face some challenges coming back from hamstring surgery but Fremantle coach Ross Lyon has no doubt the veteran ruckman will continue his decorated career next season.

The 34-year-old underwent surgery on Wednesday after coming off with tendon inflammation in the opening term against St Kilda on Sunday.

Sandilands last month signed a one-year contract extension to play on in 2018 and Lyon was "full of confidence" that the 211cm big man will bounce back.

"Does it come with challenge at his age? Yes, of course it does with the wear and tear over a long period of time," he said.

"But they've never been better conditioned, looked after and not beaten up during the week. It avails itself to play longer, we're seeing that right throughout the League. 

"It's a legitimate question with his age and profile, but certainly it can be done – and will be done."

Lyon praised Sandilands as a "special person" whose leadership, and mentoring of raw youngster Sean Darcy, would remain invaluable next season.

Darcy has made an outstanding start to his career – averaging 15 disposals and 36.5 hit-outs in two games – and looks set to shoulder the ruck load against North Melbourne star Todd Goldstein this Sunday.

Lyon confirmed Harley Bennell was aiming to make his much-anticipated comeback for Peel next Saturday.

The 24-year-old hasn't played since March last year after repeated setbacks with his troublesome calves.

"We're not expecting miracles – there will be no judgement on form," Lyon said.

"If he plays next week … he can build and maybe get a handful of senior games before the end.

"On the surface he's excited, but underneath there would be some anxiety, I would think."