GREATER Western Sydney's atonement starts against the lowly Brisbane Lions – and it requires added midfield grunt.

There was a lot missing in last weekend's shock loss to Collingwood, according to coach Leon Cameron.

The Giants struggled to cope with the Magpies' pressure, especially during poor second and third quarters Cameron described as the team's "worst 60 minutes of the year".

Part of that was an imperfect defensive display that left the Giants stuck in their own half and dried up goal-scoring opportunities.

"But that's on the back of not enough grunt around the midfield," Cameron said.

"It starts around the middle of the ground and there's no doubt that (Shane) Mumford, (Callan) Ward, (Dylan) Shiel, (Stephen) Coniglio, (Toby) Greene, (Josh) Kelly and these sorts of guys are keen to atone for where they left it last weekend."

The upset sent the third-placed Giants sliding to seventh, but they can leap back into the top-four with victory over the Lions at the Gabba on Sunday and even overtake the Sydney Swans following Thursday night's narrow loss to Hawthorn.

The Lions, who are fighting Essendon to avoid the wooden spoon, were dealt their 11th consecutive defeat in last Saturday's loss to fellow battlers Gold Coast.

Justin Leppitsch's side are the League's worst defensive outfit and have struggled against opposition forwards, priming them for a belting from key forwards Jeremy Cameron and Jonathon Patton, who booted eight goals between them against the Pies.

Cameron hoped his forwards would be given more scoring opportunities this time.

"It's a huge challenge. Brisbane have a number of players who can take it up to anyone so it's going to be a good opportunity to bounce back on Sunday," he said.

"We've trained pretty well. There was lots of spirit and contact in our main session on Thursday and we expect that on Sunday against the Lions."