Collingwood's ability, or otherwise, to overcome the unwanted distraction of Jordan De Goey's off-field dramas looms as a key factor in the AFL clash with GWS.

The Magpies are eyeing off a surprise finals tilt after posting four straight wins - three of those against top-four contenders - before the bye.

And they will be warm favourites against the also-ran Giants at the MCG on Sunday.

But De Goey's ill-fated trip to Bali and heavy scrutiny in the fallout have thrown a spanner in the works.

The explosive forward-midfielder is out of action for an indefinite period, having been granted personal leave.

"Our group has had an ability this week to just keep an eye on the ball," Magpies coach Craig McRae said.

"We have game plans to master so we've put our energy into that and we've trained as good as we have all year."

The proof will be in the performance, and GWS are braced for a galvanised opponent.

"They're in red-hot form, they've been able to play some really exciting footy and their supporter base will come out and support them through a difficult time," Giants interim coach Mark McVeigh said.

"We expect a really challenging game and that's what we're after.

"We don't shy away from that, we hope this is 50-60,000 (fans) at the MCG, a really strong atmosphere, and we want to go head to head with them."

Tasmanian midfielder Isaac Chugg will debut for Collingwood in place of De Goey, while GWS have made four changes to their side.

Phil Davis and Tim Taranto return from injury and former Magpies tall Lachlan Keeffe has been named in the ruck, with Braydon Preuss (suspension) and Matthew Flynn (injured) unavailable.

Keeffe will come up against Darcy Cameron and in-form ruck-forward Mason Cox, the American Pie who gained Australian citizenship this week and poses a "massive" threat to the Giants.

"He can go into the ruck and be damaging but he's also done a lot of damage as a forward," McVeigh said.

"His movement's outstanding for a big guy, he's covering the ground really well and he marks the ball at its highest point.

"We're going to have to be right onto him."

McVeigh believes GWS (4-9) have "underachieved" this season but they have found some decent form since he took over from the departed Leon Cameron, with two wins from four games.

Defence is an issue, however, as the Giants have coughed up an average of 93.5 points per game in that period while trying to promote a new attacking brand.