North forwards coach Shane Watson says there’s some uncertainty about how Greater Western Sydney’s backline will function this Saturday after its horror injury run last round.

The Giants will face the Roos without four of their experienced regulars, with co-captain Phil Davis (ankle), Joel Patfull (ribs/punctured lung), Stephen Coniglio (shoulder) and Shane Mumford (ankle) all sidelined for extended periods.

In attacking 50, the Roos would’ve had to contend with key defenders Davis and Patfull, who have 266 games’ experience between them.

Their absence has opened the door for 194cm key defender Caleb Marchbank – the No.6 selection in last year’s national draft – to debut for the Giants.

Watson said North’s forward group would receive as much advice as possible in the lead-up to the game, having not had a first-hand taste of playing on the likes of Marchbank.

“Anyone of our forwards can talk about Davis and Patfull because they’ve played against them and watched them for years, whereas our guys will be more reliant on us [the coaches] to give them the information,” Watson told NMFC.com.au.

“We just have to make sure we go through their vision and give the players knowledge on how they need to go about beating them.”

Watson said the Roos’ list management and recruiting teams would liaise with the coaching group about Marchbank’s defensive traits, especially after having watched the youngster at last year’s Under-18 Championships and TAC Cup.

But Watson said the Giants’ new-look backline wouldn’t have a huge bearing on how the Roos prepare for the round 12 clash.

“The approach won’t be any different other than we know they’ve lost some experience out of there and, like we do every week, we try and look at how we can exploit them with our strengths but also have a look at what they do well,” he said.

“It’s more that we know less about these guys than we know about the experienced ones that are injured.”

Defenders Nick Haynes and Matt Buntine look set to assume greater responsibility and fill the deficiency in the Giants’ defence this weekend.

Key backman Aidan Corr and rebounding defender Curtly Hampton, who both featured in the NEAFL last week, could also slot into their back six.

Watson said the Roos would be best prepared for whoever is named for the Giants, but the real priority for North was its ball delivery inside forward 50.

“The guys they bring in are no dummies; it’s just that they’re less experienced guys that we’ll be up against,” he said.

“Most of the battle in terms of putting their key defenders under pressure will be about the quality of our entries inside 50.

“If they’re poor quality or they’re pressured, they’ll hurt us.”