GREATER Western Sydney shot itself in the foot in its capitulation to its cross-city rival Sydney, midfielder Josh Kelly says.

The famous 'orange tsunami' was nowhere to be seen as a slick Swans unit outworked GWS to claim a 29-point victory and bragging rights.

Sydney, adjusting best to Saturday's wet weather conditions, dominated clearances (43-31) and contested possession (168-152) while lapses in concentration proved costly for the Giants.

The Giants' woes were illustrated when a starting position infringement in the dying seconds of the third quarter proved costly.

Tom Papley scored easily following the infringement, leaving GWS coach Adam Kingsley unable to contain his frustrations on the bench.

"There was a bit of shooting ourselves in the foot," Kelly said on Monday.

"We have to acknowledge how good the Swans were on the weekend, probably played the weather as it came in a little bit better than us. 

"At the same time, we feel a lot of it is within our control and we probably didn't play to the standard we would have liked.

"Regardless of who is out there, conditions, whatever it is, you've got a game of footy to win.

"We're not always going to get it on our terms and we're not always going to execute the 'tsunami' to absolute perfection.

"So being able to understand what we do in those situations ... is probably the thing we'll look at the most.

"That's on us as players to be better."

Kelly added losing midfield bull Tom Green, when Stephen Coniglio (knee) was already unavailable, did not help their cause.

Green left the derby in the first term after a tackle by Sydney's Hayden McLean on Finn Callaghan inadvertently caught his left ankle.

"It's a big part of it. It's not an ideal situation to be in but we still expect to get the job done," Kelly said.

"Tom going down – he's probably our main ball-winner and our main presence around stoppages.

"We probably just didn't handle that as well as we would have liked."

Scans on Sunday afternoon cleared 23-year-old Green of structural damage, though he will still need to pass a fitness test later in the week to feature against Essendon at Marvel Stadium on Saturday.

Coniglio is expected to return after recovering from a small medial collateral ligament tear.

But GWS will be without goalkicker Callum Brown for three matches following his bump on Sydney's Tom McCartin in the second quarter.

The incident was assessed as careless conduct, high impact and severe contact, meaning Brown will miss the Giants' clashes against the Bombers, the Western Bulldogs and Geelong.