The long trip to Perth is likely to be the beginning of the end for the Blues, who still hope to make the play-offs, but lying as they are in 10th and with matches to come against the Force, Crusaders and Chiefs, they are unlikely to. They are yet to win away from home this season.
A boost is the form of All Blacks Tony Woodcock, Jerome Kaino, Ma'a Nonu and Patrick Tuipulotu and another is the impending return of Piutau, who has been out with a knee injury since the defeat to the Chiefs in New Plymouth early last month. Piutau's medial ligament problem kept him out of the series against England, but Kirwan expects him to be available to play the Crusaders in Christchurch next weekend.
"He's probably about 85 to 90 per cent right now," Kirwan said. "He has good mobility in the leg and was keen to be involved this weekend but it's better to wait."
Kirwan expects all of his returning All Blacks to be available to start, including Charlie Faumuina, who was ill on Tuesday.
Fellow prop Woodcock also has an important role to play. "I thought he had an outstanding series, one of the unsung heroes," Kirwan said of Woodcock. "He was pretty tired and pretty beaten up. Hopefully he will be ready to go, we'll just see how he gets over this trip. If those All Blacks can play with the form they've been in that's really going to help us."
Kirwan said the Blues would advertise for two new assistant coaches to replace Mick Byrne and Graham Henry over the next fortnight.