Despite figuring again during the summer internationals, Spies lost out to Joe van Niekerk for a place in the starting XV for the recent back-to-back matches with the All Blacks in Wellington and Dunedin.
"It's an honour, a real privilege and it's just great to be back in the team," Spies told the Cape Argus.
"One only really realises how much one misses it when you're not part of it.
"Sure, I've been part of the squad, but it's different being part of a winning squad and being part of a winning team.
"This team we have here is a great one and the fact I haven't played yet on tour has definitely made me more eager and motivated to do well against the Wallabies."
Although clearly excited to be back in the fold, Spies knows he is unlikely to face an easy ride against a Wallaby side playing their first Tri Nations fixture under new coach Robbie Deans.
"We're going to have an active game on defence, that's for sure.
"They like to play the game at a quick pace so there's going to be a lot of work for us to do on Saturday.
"They're always probing and looking for gaps and in fly-half Matt Giteau they have one of the better number ten's around.
"He's their playmaker so it goes without saying we're going to target the nine, ten channel.
"But while they enjoy keeping ball in hand and setting up the phases, they're not going to shy away from the physical confrontation."
Australia versus South Africa is live on Sky Sports this Saturday morning (kick off 11.05 am).