Hansen believes Smith and Waugh are similar players but feels the latter's time in the international wilderness will make him "hungry" to perform against the All Blacks.
"He's not dissimilar to Smith really," said Hansen. "Both of them are very outstanding flankers so he brings a similar game to Smith.
"What does he bring that is extra? I guess he is hungry. He hasn't played too many Test matches this year and he's been given an opportunity.
"I think they are looking at coming at us from a fresh direction and with a fresh pair of legs.
"He's a leader in his own right and he's very mobile around the park."
Hansen believes Australia coach John Connolly believes Smith has been dropped to enable him to recuperate after a particularly hectic season.
"I guess Australia have played seven Tests this year and he's played in every one of them," said Hansen.
"He's got a huge work ethic and maybe they feel he needs a break."
The All Blacks battled to a hard-fought 13-9 win over the Wallabies at Suncorp Stadium in Brisbane the last time the two sides met.
New Zealand flanker Richie McCaw put in arguably his best display in an All Blacks jersey in that win and Hansen believes the imperious back-row forward is likely to be watched closely by the Wallabies pack.
"I don't think they [the Wallabies] will do anything differently in this Test than they have done in the last two," he said.
"They will try to be very physical at the breakdown and we have just got to meet that physicality.
"If they are targeting Richard, then the likes of Rodney (So'oialo), JC [Jerry Collins] and various other people in the team will get space and opportunities.
"We've got to be awake to those opportunities and that's part of playing in a team."