John Kirwan has been appointed Barbarians coach for the club's match against Australia at Twickenham on November 1.
The Blues coach will also direct the team for a game against Leicester Tigers at Welford Road on November 4.
Kirwan said he wanted to provide Australia with a test-type examination before they take on World Cup pool rivals England and Wales as well as facing France and Ireland.
"In my view it's the first test of their tour," he said of the Wallabies. "That's what they'll be expecting and that's what we want to deliver.
"It's a privilege and a huge honour to be involved with the Barbarians again.