ANGRY Brisbane coach Chris Fagan has questioned his team's mentality following Saturday's crushing qualifying final loss to Sydney.

With the Swans missing five players due to club-imposed suspensions, the Lions started the heaviest of favourites but barely fired a shot in the 53-point loss.

SWANS v LIONS Full match coverage and stats

Fagan said he warned the Lions what was waiting for them at the SCG, but "I'm not sure my players believed me".

"To be honest with you, I tried very hard this week to convince our players it was going to be a tough game … but somewhere back in the deep recesses of their mind, I just wonder whether they thought it was going to be as hard as what it was," he said.

"Sydney was magnificent. 

"They won because they were tougher, harder, they ran harder, they used the ball well. They were excellent and they should be really proud of their effort, and I'm sure they will be.

"We're not. We've got work to do."

Sydney monstered the Lions across all three lines. It smashed Brisbane's vaunted midfield, kicking six goals from centre clearances.

Early in the match they moved the ball well from defence, and ahead of the ball, the Swans forwards had a field day with Logan McDonald (six goals), Tom Papley (five) and Charlie Curnow (five) all kicking bags.

Fagan spoke to his team immediately following the loss, questioning its mindset.

"We talked about, 'Did you really think Sydney was going to be that good or did you think it was maybe going to be a walk in the park?'" he said.

"Because that's how it had been painted by all and sundry that's following football, and probably quite rightly so, but you can never underestimate the human spirit.

"And that's what Sydney showed tonight, they showed human spirit, backs against the wall, playing against a team that's been in pretty good form, and they gave us a football lesson."

The defeat leaves the Lions in exactly the same position as they were 12 months ago after Geelong belted them in the qualifying final.

They will now host either Adelaide or the Western Bulldogs in a semi-final at the Gabba next weekend and are now walking the tightrope.

"That's the key thing now, is bouncing back," Fagan said.

"What's happened tonight has happened. It's a very disappointing performance by us.

"I'm looking forward to a really positive response next week. 

"The only way we can do it now is the hard way. We have no other choice.

"The ball's in our players' court. How badly do they want it? We'll see next week."