The Lions expect a decisive battle of their miserly defence and the Crows’ potent forward line at the Gabba on Sunday.

Brisbane’s two-time club champion Joel Patfull sees Sunday’s AFL clash with Adelaide simply.

Integral to the Lions ever-improving defensive unit, Patfull knows it’s at his end of the Gabba that will decide proceedings, and possibly end the inconsistent Crows’ finals hopes.

“It will be their offence against our defence,” he said.

“They’ve got a lot of weapons, the Crows, and they’ve had some pretty high scores in the last few weeks and we’ve been able to keep teams to low scores so it will be interesting to see how it all pans out.”

With three wins from their past five matches, the Lions have completely turned opinions about the battling club.

After losing nine from their first 10 and leaking the most points in the league, they have been the second most miserly defensive team over the past month, behind just Sydney, conceding just 66 points per game.

However, Patfull and coach Justin Leppitsch know they face their biggest challenge against a Crows’ forward line that features Taylor Walker, Josh Jenkins and Eddie Betts.

Walker has particularly troubled the Lions in the past, kicking 15 goals from six matches.

“They always come out all guns firing,” said Leppitsch.

“They’re a very straight, direct and fast offensive team which means our defence has to be the same to match them.”

Leppitsch credits the consistency of selection of his back seven as well as the rise of rookies Darcy Gardiner and Daniel McStay for the Lions’ turnaround.

Patfull, who has won the past two Murray-Merrett Medals with little fanfare, has been central with his speed, organisation and ability to intercept.

“He does the job every week and he beats every player he ever plays on,” Leppitsch said. “He’s been exceptional the last 12 or 13 weeks.

“He’s a terrific player and very reliable – someone coaches love to have in their team.”

The 29-year-old, who supported the Crows as a kid, was among several senior players struggling at the start of the year as the Lions, still bedding down a new game plan and blooding rookies, lost their first five matches.

“It was always going to be a challenge to get that all sorted quickly,” he said. “It probably took us a longer than we expected to in the first 10 weeks.

“Early on I was definitely trying to do a little bit too much but actually wasn’t doing much at all.”

Now with the youthful Lions gelling, the future is looking far brighter than their 15th place on the ladder suggests.

“We’re on the up,” Patfull said. “If we could sneak another couple of wins everyone would think we’ve had a pretty positive year.”

Brisbane will expose their ninth rookie this season on Sunday with 198cm forward Jono Freeman to debut.