Alternate five eighths Baden Kerr and loosehead prop Tim Perry produced strong performances in that match but the selectors decided to return to the group who began the season with such a rumble.
Coach Kirwan has warned his young side to expect a "WWF" type battle from a Waratahs side who are under siege for their lack-lustre work this year.
A solitary win has increased the blowtorch on new coach Michael Cheika and his playing group who have shown mixed signs about raising their standards this season.
They bombed a number of chances last week against the Cheetahs and now sit at the bottom of the Australian conference.
Meanwhile the Blues see victory as vital for them to reinvigorate their campaign after a loss to the Bulls then a bye last round.
They are sandwiched on points between the Chiefs and Crusaders in the NZ section and must nail this match before hitting a run of successive domestic inquiries from the Chiefs, Highlanders and Hurricanes.
"We really need to get over there and get the points and get home because we've got our conference games coming up and every one's a big one. They're under the pump, they haven't been going so well so it's a big game for them. It makes for a pretty big afternoon for both sides," Kirwan said.
The Waratahs are a huge side so the Blues will need to implement the lessons they got against the Bulls when they failed to take the game away from their arm-wrestle threat.
Blues: Charles Piutau, Frank Halai, Rene Ranger, Francis Saili, George Moala, Chris Noakes, Piri Weepu, Peter Saili, Luke Braid, Steven Luatua, Ali Williams (c), Culum Retallick, Charlie Faumuina, James Parsons, Tom McCartney.. Reserves: Quentin MacDonald, Angus Ta'avao, Anthony Boric, Brendon O'Connor, Jamison Gibson-Park, Baden Kerr, Jackson Willison.
