Flexibility and adaptability were buzzwords of the 2020 AFL season, and they continued to ring true for GWS key defender Lachie Keeffe in round one.

Keeffe has adjusted to plenty of curve balls throughout a 72-game career that started in 2008 when he was recruited by Collingwood.

The 30-year-old underwent a knee reconstruction in 2012, while a two-year ban for testing positive to clenbuterol threatened to usher him into retirement before the GIANTS offered him a career lifeline in 2017.

Keeffe has played in defence throughout most of his time at GWS, including recent pre-season fixtures and training.

Coach Leon Cameron threw the big man up forward and into the ruck last Sunday, when he booted an impressive clutch goal in the fourth quarter as GWS almost snatched victory in a thriller against St Kilda.

The logic was to give debutant ruckman Matt Flynn and Harry Himmelberg, otherwise the only key target in a new-look forward line, some support.

"I'm not too sure how long it'll last or what's going on with a few of the injuries and boys potentially coming back," Keeffe said as the GIANTS prepared to fly west for Sunday's clash with Fremantle.

"My main position will likely be as a key defender.

"But I ultimately just want the team to have success.

"If that means playing in the ruck, defence, on the wing or wherever it might be, I'm more than happy."

Keeffe has pinch hit in the ruck previously, but enjoyed a quick refresher thanks to veteran teammate Shane Mumford .

"I usually try to steer clear of Mummy's advice - 'yeah mate, just go out there, run around, have a bit of fun, hit some bodies' - no, he's pretty good," Keeffe laughed.

"As rough and tumble as it might look when Mummy is running around, he's actually technically and tactically quite savvy.

"He had some great advice.

"Flynny was giving me feedback and we were bouncing ideas off each other during the game, which was great from a first gamer."

Keeffe argued there were promising signs in his club's round-one defeat, especially their contested-ball work.

"It was a disappointing result," he said.

"But we have ultimate belief that we'll see some fruits of our labour come the pointy-end of the season."