The 19-year-old, who played the first four games of last season before making another four appearances throughout the year, says he's been working hard since Christmas to increase his aerobic capacity and boost his ability to withstand the AFL's demanding midfield.
He has been back in full training since Christmas and is confident he is in a good place to push for selection early this season.
"I'd love to [play more seniors]. It's what I'm here for; I'm not here to play VFL footy," he said, after the Cats' NAB Cup loss to St Kilda.
"I'm kind of naturally fit, which is really good, and I've got so many good guys around me that push me to the limits and they're the ones who get the best out of you.
"I work pretty hard with Joel Selwood and he leads up the running, and Simon Hogan and Cameron Ling; you've just got to try and beat them, or stick with them anyway.
"It's pretty hard though. It's amazing to learn off all the boys."
Duncan was drafted by the Cats at pick 28 in the 2009 NAB AFL Draft and spent last season playing mainly as a small forward.
He was thrown into the midfield against the Saints in his first hit-out against the grand finalists of the past two seasons and tasked with running with elite and experienced ball-getter Lenny Hayes.
After acquitting himself admirably with 24 touches and one goal - as well as being coach Chris Scott's standout player - he said the challenge of mixing it against the Saints' premier gut runners was invaluable and helped him to work on his versatility.
"For me personally, it's a good wake up call for where I have to get to and how strong some of the boys are out there when you play in the midfield on guys like Goddard and Hayes," he said.
"It bring you back down to reality, really, and it's set the benchmark pretty high for me with where I've got to be come round one."
First-year teammates Cam Guthrie (seven touches) and George Horlin-Smith (five) also won the approval of their rookie coach for their composure under fire in what was a largely lop-sided game with the majority of the Cats' best 22 sitting out.
Duncan said both players - along with fellow draftees Billy Smedts and Jordan Schroder - had the ability to put pressure on the senior group throughout this season.
Mitch Duncan is a $278,200 forward/midfielder in this year's Toyota AFL Dream Team competition.
