GREATER Western Sydney's blue-chip midfield needs to re-ignite the team's season against the Swans in Saturday night's crucial derby at Spotless Stadium. 

Giants star Dylan Shiel believes the onball division has been a perfect reflection of the side's form in recent weeks, and they need to bounce back against the surging Swans. 

GWS were ladder leaders for rounds 14 and 15 but haven't been the dominant team that most expected them to be, with injuries putting pressure on the club's second-tier players to step up. 

Across their past four games the Giants have won the clearances, but lost the contested possession count to Carlton (round 12) and Hawthorn (round16), and lost the clearances, but won the contested ball against the Brisbane Lions (round 13) and Geelong (round 15).

They've won just one match against the lowly Lions, lost to the Blues, and drawn their past two against the Cats and the Hawks, and Shiel said it was that type of inconsistency that was hurting his team 

"You don't have to be Einstein to work out that we're not playing the best footy we're capable of at the moment, so we're working as hard as we can to rectify that," he said.

"The midfield is probably similar to the team, we're inconsistent with our performances over four quarters, and our depth has really been challenged in that area. 

"Over the last couple of weeks Geelong and Hawthorn have been able to quell our strengths in the midfield, but we've reviewed it like we do any other week, and hopefully we can get some more drive this week. 

"There's no doubt that contested footy is a big strength of the Swans and over the last couple of months their football club has been No.1 at it."

Shane Mumford will be a significant factor in the second derby of the year and will be looking for a big game after a month or so of indifferent performances.

Mumford has had his colours lowered around the ground by the likes of Carlton's Matthew Kreuzer, Brisbane Lion Stefan Martin, and Hawthorn's Ben McEvoy. 

The veteran won the Brett Kirk Medal when GWS beat the Swans by 42 points in round five at the SCG, and dominated Kurt Tippett and Callum Sinclair with his physicality. 

"Shane is a massive influence on our football club and particularly our midfield, and when he's up and going, everyone knows that he's crashing packs," Shiel said.

"The way he attacks the ball and attacks the man is definitely the best I've ever seen, and we're hoping he'll be up and about from the very start on Saturday night.

"His influence is fantastic for us."