All Black prop Charlie Faumuina and loose forward Steven Luatua, and former All Black Piri Weepu, will begin their season by playing in the Blues' final trial against the Chiefs in Rotorua on Friday.
Charles Piutau, Francis Saili and Frank Halai opened their account in the 33-12 loss to the Waratahs last Friday night in Sydney, a match notable for the Waratahs' size and experience - they fielded several Wallabies including Israel Folau, Kurtley Beale and Adam Ashley-Cooper - as well as Benji Marshall's continuing learning experience at first-five.
"They were a little bit better organised than us at the breakdown, which we haven't done a lot of work on and are due to do this week," Kirwan said. "We were under the pump early with a few penalties [seven in the first 20 minutes].
"The Australian sides are always ahead of us at this time of year because they get together a lot earlier."
Former All Black lock Tom Donnelly, in his first game for the Blues, was the most experienced in Kirwan's pack.
Kirwan said of Marshall on his return to the city where he lived for 14 years and carved out a long and distinguished career at Wests Tigers: "He learned a lot again. He's the type of guy who learns a lot by playing."
Marshall said afterwards fellow code-swapper Folau had suggested starting his rugby career at fullback, but he wanted to concentrate on No10.
"I want a challenge at 10," he said. "It's been a rapid development considering I was given no chance. I'm happy with where I'm building it.
"The expectation has been massive but you've just got to embrace the expectation and try and get better."
In other pre-season games played by New Zealand teams, rookie first-five Ihaia West scored a try as his Chiefs side lost 31-20 to the Reds in Toowoomba. The Reds ran in four tries against the back-to-back champions.
In Geelong, Hurricanes loose forward Brad Shields suffered a knee injury in his team's 24-22 loss to the Rebels. The Hurricanes outscored the Rebels three tries to two.