CHRIS Fagan has pinpointed the areas slow-starting Brisbane needs to address ahead of hosting Collingwood on Thursday night, saying incredible second-half comebacks were "not sustainable" across a season.

The premiership coach is delighted with his team's 5-0 start, but said the Lions could not continue giving up big leads and expect to remain undefeated.

They have won the past eight times when trailing at half-time, including big reversals against West Coast, Geelong and the Western Bulldogs already in 2025.

Ahead of his team's captains' run on Wednesday morning at the Gabba, Fagan said he had a couple of theories on why Brisbane had been caught trailing so many times.

"Maybe you could say it's a readiness to play, maybe it's what the opposition throw at you," he said.

"Oppositions are coming at us a lot harder than what they have in the past.

"If you want the technical side of it, contested ball has probably been down in the first half of games, and our workrate.

"We've just got to get that better.

"It's not like we're not good at that, we're actually really good at it, we just haven't done it as well in the first half for some reason or another."

After slow first quarters against Sydney and the Eagles to start the season, it was second-quarter avalanches from the Cats and Dogs that had put Brisbane in a hole.

"The good thing is we've been able to muster the effort in second halves of games to find a way to win, but doing it that way is not sustainable, and we know that," he said.

"We'll keep working away at being more consistent throughout a game, which I think is a pretty hard thing to do these days because all the teams are pretty good and they're going to get their moment in the sun."

Brisbane is out to break a three-match losing streak against the Magpies in their traditional Easter Thursday timeslot.

The hosts will likely be unchanged, opting to give dynamic small forward Kai Lohmann a third straight match on the sidelines to overcome a nagging ankle injury.

Fagan said Collingwood tested you "every which way".

"It's not like they've dominated us, it's just that they've been able to do the moments a little bit better, I reckon in those closer games," he said.

"It's a different year this year and we've got an opportunity to change that trend, so we'll try and take it."