It is understood Counties Manukau coach Umaga has told the province's chief executive Andrew Maddock that he will not be returning. Maddock yesterday did not respond to an invitation to comment.
Yesterday's press conference to announce Kirwan's decision to step aside, organised at short notice after he made up his mind the day before, drew the curtain on what the former All Blacks wing called a "perfect storm" of a year.
Kirwan recounted how he walked into the role with a light heart after 12 years of preparing for what he called his dream job.
Three years later, that dream is in tatters and, in announcing his decision to walk away, it was his first statement that perhaps was the most significant.
"I totally love this club and I believe for it to succeed in the future it needs total cohesion from all its stakeholders," he said.
In the end, half the board was against Kirwan, and so were many of his players. The bottom line was he had to go because his message wasn't getting through to the men on the field and he wasn't being fully backed by his employers.
Kirwan, who presided over only two away victories during his tenure, said he would talk about his future with his family but coaching was not high on his agenda.
"I've got to make some decisions around that," he said. "I've got other passions in my life and I have to take some time out with my family. When you do this job it's 24/7 and it has been tough on them as well. I'm just going to take some time.
"Rugby is my passion, it's what I do, I love it, but I'm certainly not sure what I will do moving forward."
In paying credit to his former head coach's contribution to the franchises, Redman pointed to Kirwan's off-the-field work.
"When he arrived here three years ago, JK had the courage to shine the spotlight on a whole number of things in this organisation which were in urgent need of reform and while the playing results under JK have not been what he or we would like, it in no way reflects his efforts, hard work, contribution and determination to try to turn this club into one which will have sustained success," Redman said.
Kirwan added there would be more pain at the Blues before it got better. That's not his problem any more. After many sleepless nights this year, the relief on his face yesterday was clear.