"This city is crying out for a brilliant number 10, and if he came up here and delivered what we think he can with Sonny Bill... he could become a hugely popular figure in a city that is crying out for its rugby team to get back on top," Kirwan said.
"If he comes to the Blues and we end up winning, who gets the credit for it? He would."
Kirwan also said it was the perfect time for Barrett who would also be vesting his off-field interests in a city that is far more prolific.
"This is the place to be commercially," Kirwan said.
"Look at Daniel Carter, he's hanging out with Lewis Hamilton and people like that, and the place you can do that is Auckland."
Kirwan confirmed the franchise had already tried to chase Barrett's services previously, jokingly remarking they had offered him the Skytower and Harbour Bridge to come and play.
Now, Kirwan sees Barrett as the final step towards a successful franchise.
"We need that kind personality to drive our football team," he said.
"It would be the final part of the puzzle."