The 23 year old had initially been booked to open for Beyonce on all her Australasia dates, but she had to drop out of the New Zealand shows for an undisclosed reason.
Confirming the news on her Twitter.com blog, she writes, "Yes, Iam (sic) missing the Nz leg of the Mrs Carter Tour. I personally really wanted to come, but sometimes I don't get to make the choices."
Antipodean star Walker has been hired in Azalea's place and admits it's a dream come true.
Taking to his Facebook.com page, he writes, "Never in my life did i think that my dream 2 meet beyonce or open for her would come true. But i can finally announce with more excitement than you even know that i will be opening for the Queen in New Zealand on her tour. Life complete... Hahahaha praise Jesus (sic)."
Beyonce takes her Mrs Carter Show World Tour to New Zealand from 16 October (13), before heading to Australia from 16 October (13).