While Melbourne and Brisbane deliberate over how they'll set-up defensively in Saturday night's qualifying final, newly recontracted Lion Marcus Adams says the game will be decided elsewhere.

When they met for the only time this season in round 12, the Demons turned a 20-point half-time deficit into a 22-point victory – something Adams says the Lions will address as the week unfolds.

"I think the contest turned around a lot (that night)," Adams said.

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"In the first half it felt like we were getting the ball going our way from stoppage and contest a lot.

"The second half, they've got some great players and so do we, so when they get on top they can play some amazing footy - you don't finish on top for no reason.

"And our midfield as well, when they get on top they can get us going forward repeatedly.

"I felt like that was the shift from my end, and then they move the ball extremely well, which is no secret to anybody."

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After five weeks on the sidelines with a foot injury, Adams returned to Brisbane's back six against West Coast at the weekend, immediately showing his value with a strong outing.

He was a late inclusion for Harris Andrews (hamstring), who will now have to be reinserted this week, while Melbourne wrestles with whether to include veteran Michael Hibberd.

Just days after his return Adams has inked a two-year contract extension that will keep him at the Gabba until the end of 2023.

His 15 games this season is the most in any of his six years in the AFL, with a broken foot wiping out all bar one game of 2020.

"I said to the boys that about six months ago I thought I was going to be standing in front of them saying 'thanks for the memories'," Adams said.

"At the start of the year I wasn't expecting it. I guess I was lucky to string a few games together and very fortunate to get a new deal.

"I felt like I was letting everyone down on a continual basis, I sort of wanted to hide away in the shadows a bit too. 

"It's been great to get out there and repay a bit of that faith over the last three or four months."