A victory over the Wallabies at Twickenham next weekend would put them through to a Rugby World Cup semi-final for the first time since 1991.
And with Scotland having beaten Australia twice in their last three meetings, Strauss - who is set to miss Glasgow Warriors' GUINNESS PRO12 encounter with Newport Gwent Dragons on Friday night - is confident.
"We're ready to take on anyone who comes," Strauss told ESPN.
"I've said it 100 times and it may be a bit of a cliché, but you don't go into any competition not believing you can win.
"At times we didn't do our jobs against Samoa, but they're great ball players and they take their opportunities.
"We kept cool heads at half-time and now feel a lot of relief after a long two-and-a-half months. A lot of work has gone into getting where we want to be.
"The belief is there and there's a lot of hard work still to do, but this will be a great confidence boost to the squad.
"Lifting morale is so important because four weeks is a long time to spend in a hotel and it does get a confined at times, but this is just what we need."
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