Lessons learned from the lowest point in his life have steeled Brisbane Lions utility Jared Brennan for the biggest game of his AFL career.

Brennan was all smiles on Tuesday when he talked about running out for his 100th game on Saturday night at the Gabba - in the Lions' first finals game in five years.

And the grin only got broader when he noted that it would be his first finals game.

It took him six years to reach game No.100.

But it took just an instant to earn another telling career milestone - his first suspension.

The usually laidback Brennan shocked everyone - including himself - when he reacted to constant Josh Carr niggling by landing a now infamous headbutt on the Port Adelaide player in July.

It proved a turning point in the match as Port overran Brisbane by 47 points - but it had much more serious consequences.

Brennan copped a one match ban, but it is what he copped when he got home that hurt the most.

"It was the most embarrassing time of my life, not only for myself but for my family, my daughters - that was the tough thing," Brennan said at Brisbane on Tuesday.

"It was a very, very long flight home from Adelaide after the game.

"Getting home and going over it a million times in my head was hard, then having to front up to my family and friends was even harder."

But Brennan said he emerged a better player after "a lot of soul searching".

"It was very much out of character, it was an awkward situation that I hadn't been in before - I had never been suspended before," he said.

"I had to take it (the ban) hour by hour, day by day and just learn from it - I'd like to think I am a better player for it."

After proving a thorn in Carlton's side in the past, Brennan said he wouldn't be surprised if the Blues wanted to niggle him in their knockout final on Saturday night.

But this time, he will be ready.

"It's finals football now so you've got to expect everything," he said.

"(But) I learnt a lot from the Port Adelaide game niggling-wise.

"Just how to react to it, know that it is going to come.

"It's something that you have to put up with."

All the hard work, all the tough lessons learned will be forgotten when Brennan runs out for a milestone match in a rare finals game for the Lions.

But Brennan admits he won't feel like celebrating his personal achievement on Saturday night.

"I would probably prefer to play my 100th during the season because it is not really about me at the moment, it's about the team," he said.

"If I think `gee I am playing my 100th in a final, it's wonderful', it's kind of the wrong way to go about it.

"The team has to come first.

"We will be on holidays on Monday or they will be on holidays on Monday - we need to get the win, that's what it is all about."

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