GREATER Western Sydney ruckman Shane Mumford says the ankle he seriously injured last season will never be 100% again, but declared himself a certain starter for Friday's NAB Challenge match against the Sydney Swans.

Mumford's left ankle collapsed in a marking contest against Collingwood in round 11 at the MCG last year, and he spent the next two months in a cast. 

The aggressive ruckman – arguably the Giants' most important player – was forced to look on as his side dropped out of finals contention, winning just four more games in his absence. 

Ahead of his first senior game in almost eight months, the 30-year-old said he had accepted the fact that he would be forced to carefully manage his workload and recovery for the rest of his career.

"I think my whole body has got pain in it these days - there's not really anywhere that doesn't. It's just about managing how much pain (I have)," Mumford joked.

"There'll always be ongoing maintenance so I've just got to continue to keep on top of it with my rehab exercises.

"I'll try and get as much out of this week as I can, I'll probably try and stay out there and they'll try and drag me off.

"To get a good hit-out this week and next week is crucial going into round one, because no matter how much training you do, match fitness is completely different.

Mumford hopes to play around 70 per cent of the game against the Swans at Drummoyne Oval in Sydney's inner west, before stepping up his output when GWS take on the Brisbane Lions at Metricon Stadium on Sunday March 13.

The No.1 big man will work in tandem with promising youngster Rory Lobb against in-form Swans pair Kurt Tippett and Callum Sinclair.

Coach Leon Cameron confirmed three-time Geelong premiership forward Steve Johnson would also face the Giants' cross-town rivals in his debut match for the club.

"No doubt there'll be a few nerves, he's going to put on a different jumper to the one he's worn for the last 13-14 years, but he's not going to be nervous because he hasn't done the work," Cameron said of Johnson.

"He's had a really good pre-season, he's an exciting player and we want him to lead our young forward line.

"I think it's the first time he's ever been able to walk to a NAB Challenge match, because he lives just up the road. 

"It'll be a little bit strange for him walking through the streets of Drummoyne to get to the game."

Cameron will use a reduced squad against the Swans, with the Giants expected to go with 24 players instead of the regulation 26 to help with their game-time management.

Reigning club champion Heath Shaw, co-captains Callan Ward and Phil Davis, and young stars Dylan Shiel and Jeremy Cameron are among the inclusions, after they missed the club's 31-point loss to the Western Bulldogs last week.

Skillful forward Devon Smith didn't train with the main group on Thursday, instead practicing his goalkicking but is still expected to play his first match of the season.

Midfielder Stephen Coniglio captained the side against the Dogs but will miss the match with a tight hamstring, with power forward Jon Patton and academy draftee Jacob Hopper also left out of the squad.