The irony hasn't been lost on Brisbane defender Keidean Coleman that the team he grew up cheering on to a premiership is the same one he's hoping to stop from lifting the cup on Saturday.

The Lions' silky smooth half-back was a big Collingwood fan as a youngster, donning the black and white jumper in front of the television in 2010 to support them, while younger brother Blake barracked for the opposing Saints.

Now, 13 years on, Coleman looms as an integral part of Brisbane's premiership push against the Magpies following his best-on-ground performance in Saturday night's preliminary final win over Carlton.

"I was a Collingwood supporter and I debuted against Collingwood," Coleman chuckled to a packed media scrum at Brisbane's Springfield training base on Monday.

"I remember my debut game, running out against Scotty Pendlebury was surreal.

"It's pretty ironic and pretty weird to think that I'm playing a granny against Collingwood, the team I grew up supporting."

Coleman's rise has mirrored that of the Lions. 

Originally from Katherine in the Northern Territory, he moved to Brisbane as a nine-year-old before being drafted as a Lions Academy graduate in 2019.

Coleman said he was treated like a "megastar" in his hometown, with a lot of family in the surrounding areas.

They had plenty to cheer for against the Blues, with the 23-year-old gathering 21 disposals, a match-high 11 of them intercepts, and being involved in seven scores.

Coleman conceded there was a lot going on beneath his calm exterior.

"It was just one of those nights where the ball fell in my hands and I was able to use it by foot and open the game up," he said.

"I do feel a bit nervous, I do get a bit anxious.

"That's when I play my best footy… when I play on instinct.

"It hasn't hit me yet. 

"We're into a Grand Final, which is exciting, and I'm excited for the week ahead."