Coach Warren Gatland has faith that Anscombe can take on the fullback role in a test environment.
"Matthew Morgan got a knock last week so he wasn't able to do full contact until later this week," Gatland explained. "Gareth's played a lot at fullback, experienced at Super Rugby...two years ago played the Super Rugby final for the Chiefs at fullback. I like the mix of the backline. They've trained exceptionally well this week."
"He's just [a] cool head, brings a confidence and assurance, speaks well and has that pedigree of playing at the top level as well."
Gatland conceded it could spring a surprise on Australia.
"It's nice to have someone with that sort of that experience coming into the side and someone a little bit different that they potentially weren't preparing for."
Anscombe said it's been a rollercoaster month.
"Gats spoke to me last week and said there could be a chance this weekend for a run, really excited and can't wait for Saturday arvo".
Anscombe made his name as a number 10 before developing into more of a utility and acknowledges first five is his preferred position.
"I started playing a bit of 15 [at the Chiefs] when we had Aaron Cruden playing 10. Hopefully I can jump in at first receiver every now and then."
Anscombe will match up against Israel Folau, who has been cleared to start for the Wallabies after overcoming an ankle injury.
"I played 15 against the Waratahs and he climbed all over me. He's an athlete and we know the dangers he possesses."
Wales will wrap their preparation with their captain's run tomorrow.
Lineups:
Australia: Israel Folau, Adam Ashley-Cooper, Tevita Kuridrani, Matt Giteau, Drew Mitchell, Bernard Foley, Will Genia; David Pocock, Sean McMahon, Scott Fardy, Dean Mumm, Kane Douglas, Sekope Kepu, Stephen Moore (captain), Scott Sio. Reserves: Tatafu Polota-Nau, James Slipper, Greg Holmes, Rob Simmons, Ben McCalman, Nick Phipps, Matt Toomua, Kurtley Beale.
Wales: Gareth Anscombe, Alex Cuthbert, George North, Jamie Roberts, Liam Williams, Dan Biggar, Gareth Davies;Taulupe Faletau, Justin Tipuric, Sam Warburton (captain), Alun Wyn Jones, Luke Charteris, Samson Lee, Scott Baldwin, Paul James. Reserves: Ken Owens, Aaron Jarvis, Tomas Francis, Jake Ball, Ross Moriarty, Lloyd Williams, Rhys Priestland, James Hook.