McCarthy, from South Fremantle, will be the fourth GIANTS player to debut this season and the 64th player to represent the club.
The young utility who has been nicknamed "Sunshine" by teammates was drafted by the GIANTS with pick 14 in the 2013 NAB AFL Draft.
McCarthy is among five inclusions with co-captain Phil Davis and defender Curtly Hampton set to return from injury, while Liam Sumner and Zac Williams have been recalled.
Going out of the side is Adam Kennedy (shoulder), Mark Whiley (hamstring), Tim Golds (concussion), Jono O’Rourke (hamstring) and Sam Frost (omitted).
GIANTS coach Leon Cameron said McCarthy was an exciting prospect who can play at both ends of the ground.
“We recruited him as a forward, but he spent the first six months at centre half-back or as a key back,” Cameron said.
“It’s been great he’s learnt some defensive habits… but there’s genuine excitement when he plays up forward.”
“It’s great for Cam and it’s great to see him get an opportunity against the Dogs on Sunday.”
Cameron said the GIANTS defensive stocks would be boosted by the return of courageous co-captain Phil Davis who has overcome a calf injury.
“He (Davis) was nearly ready for the Collingwood game but he’s trained really well this week and we look forward to having him in that key back position.
“We take on the Dogs who are going to be up for Daniel Giansiracusa who has been a fantastic player for that football club and there’s no doubt they want to finish on a good note for him… we’re looking forward to the challenge.”
GWS GIANTS v Western Bulldogs
Sunday August 31, 4.40pm
Etihad Stadium
GWS GIANTS
FB: Lachie Plowman, Phil Davis, Adam Tomlinson
HB: James Stewart, Heath Shaw, Matt Buntine
C: Josh Kelly, Adam Treloar, Will Hoskin-Elliott
HF: Tomas Bugg, Tom Boyd, Dylan Shiel
FF: Devon Smith, Josh Hunt, Liam Sumner
R: Shane Mumford, Rhys Palmer, Zac Williams
Interchange: Nathan Wilson, Curtly Hampton, Cam McCarthy, Toby Greene
Emergencies: Jonathan Giles, Jacob Townsend, Sam Frost
In: Phil Davis, Liam Sumner, Zac Williams, Cam McCarthy (debut), Curtly Hampton
Out: Adam Kennedy (shoulder), Jono O'Rourke (hamstring), Tim Golds (concussion), Mark Whiley (hamstring), Sam Frost (omitted)
