"They [New Zealand] showed it in that first Test against us that any opportunities they get they'll punish you, any mistakes you make they'll capitalise on them," he told ABC Sport.
"So, we've just got to limit our opportunities and play our style of football."
Giteau is aware of the attributes Mauger brings to the All Blacks backline.
"He's a very smart player, very good defender and very good ball player," Giteau added.
"He helps Daniel Carter out a lot and is also a smart kicker, so he's just as important as Dan Carter. He's a great player."
All Blacks coach Graham Henry admitted the side that will battle the Wallabies this weekend was his "A team".
"This is the experienced team, isn't it, that's played a lot of Test matches together," he told reporters.
"A lot of these guys have played a lot of important Test matches together so, yeah, I think you could call that the A team."