They have plenty of ready-made excuses - the six-hour-plus flight to Western Australia, the inhospitable time difference which will see the match starting at just before midnight New Zealand time, the fatigue of prop Tony Woodcock after his exploits with the All Blacks against England, and recent illness of front row colleague Charlie Faumuina.
The fact remains, however, that while the seventh-placed Force are having an unprecedented season in terms of success, they, like the rest of the Australian teams in the Super Rugby competition are vulnerable up front.
There is a feeling within New Zealand and South Africa that if the Aussies are beaten up then they are beaten.
That certainly wasn't the case for the Blues in their defeat the Brumbies in a wet Canberra in April, but with players such as Woodcock, Patrick Tuipulotu and Jerome Kaino in their pack, the Blues should be confident of gaining the necessary edge in the collisions in Perth and of these three the young lock could be the most important.
His recent taste of test rugby against the English - he played four minutes in each of the tests in Dunedin and Hamilton after remaining on the reserves bench in Auckland - has left him hungry for more, the 21-year-old conscious of the fact that expectations have risen accordingly.
"I have to play at another level up now," he said. "In Super Rugby especially, more people will be watching me now so I have to perform.
"It's going to push me. I'm here now, it's mine to lose, so I've just got to perform."
The Blues could certainly do with a ruthless attitude, and with his size and skill around the field, Tuipulotu has the ability and physical attributes to deliver on it.
Their convincing 37-24 victory over the Hurricanes at Eden Park before the international break was one of their best of the season and once again highlighted the talent and potential in their ranks.
Transferring that away from home is a puzzle they haven't been able to get to grips with and, 10th on the leaderboard with only three matches to go, it appears to be too late for a charge to the playoffs.
A run-in including the Force, Crusaders in Christchurch and Chiefs back at Eden Park is a tough one but it will be important for Kirwan to see a continuation of the form and desire his team showed against the Hurricanes.
After rubbing shoulders with All Blacks Sam Whitelock and Brodie Retallick, Tuipulotu knows the level he has to reach is a high one.
"You watch these guys play and it's unreal to see how good they are in person; to see how professional they are, especially Sam Whitelock being the main caller in the lineout, I try to take a few things off him in that area. Brodie Retallick in the breakdown area, he's just ruthless."
The Blues team to face the Western Force at nib Stadium in Perth on Saturday night, kick-off 11.45pm NZT, is: Lolagi Visinia, Frank Halai, Pita Ahki, Ma'a Nonu, George Moala, Ihaia West, Bryn Hall, Jerome Kaino, Luke Braid (c), Steven Luatua, Patrick Tuipulotu, Tom Donnelly, Charlie Faumuina/Angus Ta'avao, Keven Mealamu, Tony Woodcock. Reserves: James Parsons, Angus Ta'avao/Tom McCartney, Ofa Tu'ungafasi, Hayden Triggs, Peter Saili, Piri Weepu, Francis Saili, Tevita Li.
- By Patrick McKendry of APNZ
