"I found out only this morning that I was playing after coming down as 18th man and straight on the phone to my wife and mum and dad. It was pretty emotional.
"They're coming down on Friday and I can't wait to run out in the green and gold in front of them."
Sheens said he'd been hopeful Thaiday would be able to play but the decision to rule him out was taken after he struggled to come through a fitness test yesterday.
"He did a little bit this morning and it tightened up a bit so we said no," Sheens said.
"Brisbane weren't too sure if he would be right, but we had to make a call early in the week and Sam was happy with that."
Sheens is yet to decide who will replace Thaiday in the starting lineup with interchange forward Boyd Cordner and Gillett both in contention to play.
Kangaroos: Billy Slater, Darius Boyd, Greg Inglis, Josh Morris, Brett Morris, Jonathan Thurston, Cooper Cronk, James Tamou, Cameron Smith, Matt Scott, Matt Gillett, Greg Bird, Paul Gallen. Interchange: Daly Cherry-Evans, Nate Myles, Boyd Cordner, Corey Parker. 18th man: Brent Tate.
- AAP