The hosts lead England 2-0 following victories in Brisbane and Adelaide, meaning that victory at the WACA will see them lift the urn for the first time since 2007.
"I'm hopeful that everyone will come up, I think there's the obvious one in Ryan-o, who bowled today, and we'll see how he pulls up," Clarke told reporters. "I'm confident he'll be fine.
"I think one of [Faulkner, Bollinger or Coulter-Nile] will come in and replace Ryan if he's not fit but, as I say, I'm very confident that Ryan will be okay."
The third Test gets underway tomorrow.