Gunston has been ruled out for Saturday's clash with Fremantle in Launceston, having struggled to train during the week after picking up a minor leg injury.

The All-Australian has battled for form this season, booting 19 goals from 15 games and just three from his past five.

Clarkson says Gunston's latest issue is "completely unrelated" to the iliotibial band injury he sustained during the pre-season.

But Gunston, one of the Hawks' most consistent performers in the previous six seasons, has struggled this year with frequent niggles.

"He's had a bugger of a year in terms of just little niggles here and there," Clarkson told reporters on Friday.

"It's stopped him from being able to produce anywhere near his best form.

"We're hoping that just by giving him a rest this week we'll nip it in the bud and he'll be able to attack the last six weeks with a bit of a gusto."

With Gunston's latest setback a worry for the Hawks, confirmation that Grant Birchall will play his first AFL game in more than two years is a major positive.

One of two four-time premiership players still on the Hawks' list - along with former skipper Jarryd Roughead, who remains confined to the VFL - Birchall has been out of action because of a serious knee injury and then soft-tissue problems.

"If there's anything to sort of get the boys up it's the fact they're playing with Birch again," Clarkson said.

"It's very unusual for a player to play 10 or 15 years of footy without one of those years being severely interrupted but when it's two years in a row, that's a pretty harsh price to pay for throwing your body into this game."

The 31-year-old is an unrestricted free agent at season's end but Clarkson said his time out of the game wouldn't count against him potentially earning a new contract.

"We need to monitor his leg and see how he responds to being able to play footy at the highest level again," Clarkson said.

"If that all goes well then the fact that he's missed two years of footy shouldn't go against him, it actually should be a plus for him - the fact that we might have a reasonably fresh player on our hands.

"We've just got to wait and see how that knee responds."

The Hawks also regain injury-plagued recruit Chad Wingard and dropped Conor Glass.

Australian Associated Press