GWS ruckman Shane Mumford could potentially miss at least the next fortnight as he tries to recover from an ongoing ankle problem.

Mumford has played all 17 games for the Giants so far this season, but has been ruled out of his side's clash with Fremantle after the pain was too much to overcome.

The 31-year-old originally suffered the injury in 2015, and missed most of that season after going down against Collingwood in round 11.

Giants coach Leon Cameron told reporters on Friday that Mumford had finally succumbed to the pain, and would likely need at least one week off.

"It's progressively gotten worse over the last few weeks and it got to the stage during last weekend's game that it was really hard for him to push through," Cameron said. 

"We had to bite the bullet and he's had a few injections to see if we can fix it up. 

"He's no certainty to return next week, it depends on how he goes later next week in his training." 

Veteran forward Steve Johnson will also be unavailable for Saturday's clash with the Dockers, after a knee injury ruled him out of the round 19 fixture.

Johnson has battled with a knee injury for a while now, and his recent form with the injury means he'll be touch and go for the rest of the season.

"There's no doubt that his knee is hanging on by a thread, but it doesn't matter how you get to the ground on game day," Cameron added.

"Whether you're 80 per cent, or 100 per cent, you get judged on that performance and rightly so, and Steve's the first person to put his hand up with that sort of thing.

"He's had such a fantastic career but he keeps finding a way, like when we played the Swans two weeks ago, and he was a really creative forward and kicked a couple of goals."Â