The 27-year-old has managed just eleven matches this season after suffering an ankle injury at training on the eve of the club's match against Fremantle in Round 13.
In what looms as a massive game for the Kangaroos with possible finals ramifications, McMahon's experience and skill could be vital when the heat is on against Collingwood.
Nathan Grima has not been named despite hopes he might have been able to recover in time for a foot injury.
Meanwhile Leigh Adams has bounced back from the knee issue which kept him out of the side against Hawthorn last week and youngster Taylor Garner is in line to play his second career game.
The final team will be lodged on Friday afternoon.
For Collingwood, Luke Ball is out while Dayne Beams, Kyle Martin, Jordan Russell and Ben Hudson are the inclusions.
The squad
B: Lachlan Hansen, Luke Delaney, Aaron Mullett
HB: Ryan Bastinac, Michael Firrito, Shaun Atley
C: Sam Wright, Daniel Wells, Sam Gibson
HF: Jamie Macmillan, Robbie Tarrant, Brent Harvey
F: Lindsay Thomas, Drew Petrie, Aaron Black
Fol: Todd Goldstein, Ben Cunnington, Jack Ziebell
Int From: Brad McKenzie, Ben Jacobs, Leigh Adams, Levi Greenwood, Taylor Garner, Will Sierakowski, Scott McMahon
In: Scott McMahon, Leigh Adams, Taylor Garner
