Veteran ruckman Shane Mumford could be called on again to lead the GIANTS midfield, this time in the Sydney Derby at the SCG on Saturday.

The 34-year-old turned back the clock in the GIANTS' 30-point win over Collingwood, when he nullified star Magpie Brodie Grundy in the absence of rested ruckman Matt Flynn.

Mumford had just 16 hitouts to Grundy's 42, but amassed 17 disposals, eight clearances and six tackles as the GIANTS shaded the Magpies at the stoppages on the way to their unexpected victory at the MCG.

The GIANTS now have a decision to make on whether to play Mumford against Sydney and its in-form ruckman Tom Hickey, or bring back 23-year-old Flynn.

"It will be a really good discussion," Leon Cameron said.

"'Mummy' is our ruck coach and player, and he's not the player that he was a few years ago.

"If everything went to plan, which it never does, he should only be playing six or seven games, because we really want to develop Flynn and [Kieren] Briggs."

"But we were rapt with his performance."

Flynn was one of the best players on the ground in his debut in round one, an eight-point loss to St Kilda in wet and windy conditions not typically suited to big men.

But with the GIANTS falling to 0-3 before the upset win over the Magpies, it was seen as time for Flynn to have a rest and for the robust Mumford to step in.

Cameron said the decision on ruck selection this week isn't a simple choice between developing a young big man and prioritising victory in a Sydney Derby.

"It's a huge game for us, where we're coming from. But you're trying to pick the best team every week," Cameron said.

"It's not as if we're just giving young Matty Flynn a game, he'll deserve to play this weekend if he gets picked. And so will Shane, but Shane just can't go back-to-back-to-back three or four weeks in a row."

Mumford played 79 games at the Swans, and won a premiership there in 2012 under John Longmire, before moving to the GIANTS at the end of the following season.

The Sydney coach knows Mumford well and is aware of what he's still capable of.

"Mummy was brilliant on the weekend," Longmire said.

"I don't think anyone was surprised by what Mummy can deliver in a competitive sense. He can certainly work himself to that point where he just goes out and gets the job done.

"He's always been like that, massive competitor, very good with his ruck craft too, able to manoeuvre and shift people out of the way really well. He's very good at his craft."