Jack Buckley gave up footy when he was 16.

Now he's taking on gun forwards like Jack Riewoldt and Jack Darling and is set for a bigger challenge against Brisbane's tall timber on Saturday afternoon. 

Buckley arrived at the GIANTS as a key forward and started this season playing on a wing, but rather than being a jack of all trades he is now being trusted with some of the toughest defensive duties in the AFL.

He most recently took on Darling, who has been one of the in-form key forwards in the competition and had kicked five goals in a quarter against Adelaide the week before. 

The West Coast forward made a strong start, kicking 1.2 in the first term, but Buckley was able to keep him scoreless for the rest of the match as the GIANTS ran out 16-point winners. Darling's one goal for the game was his lowest tally for the season.

Buckley did an equally impressive job the week before, limiting Richmond star Riewoldt to a goal and only three kicks for the match.

"I've really enjoyed getting the responsibility of those roles and appreciated that the coaches back me in," Buckley told AFL.com.au. 

"They're great players but once you're out there you're so focused on each moment and play that you can't think about what they've done in the past. 

"During the week I watch vision of how they go about it, and have a picture in my head of how they play from watching them over the years. But I have to treat them as if they're any other player when the contest is on."

Buckley will have another crucial role against the Lions and their formidable forward group that includes Joe Daniher, Eric Hipwood and Daniel McStay, especially now that his teammate Sam Taylor is sidelined with an ankle injury.

At 194cm and 90kg, Buckley will be undersized against Daniher (201cm) and Hipwood (203cm) but has already shown this season that he can compete well with bigger bodies.

"We'll have a plan for those guys. We do a lot of work with [assistant coach] Adam Schneider figuring out individual match-ups and how we each go about that," Buckley said. 

"You might be giving up a bit of size but there are always certain techniques that you can use to cover that, to compete in the air as much as you can and bring the ball to ground. We'll go in confident as a backline, as we have for the past few months."

The GIANTS plucked Buckley from Sydney's premier competition as a locally zoned category B rookie in late 2017, but it took until the second-last round of 2020 for him to make his debut. Buckley held his spot for the following week and has since lined up in all 10 rounds this season.

The 23-year-old admits to having plenty of doubts about whether he was up to the elite level, and even gave up football for basketball when he was 16 and sick of watching on as his teammates at the Swans Academy played for the state and other rep teams.

But the son of North Melbourne chairman and 74-game player Ben Buckley is looking settled in an inexperienced GIANTS defence that is missing regular key defenders Phil Davis, Lachie Keeffe and now Taylor.

"It took me a while to get that first game, took me a few years, so now it's just about building on that and getting that belief and confidence," Buckley said.

"Now I'm just finding all the areas to improve on each week. Defensive positioning is the main one, and body work. 

"We're young but we've got a tight bond down there. We can give each other good feedback and everyone takes it well because we're all good mates who have each other's backs, and that's holding us in good stead."