The Blues loose forward and 21 test All Black Akira Ioane will head to Japan at the end of the season.
The club has shared on social media that Ioane is leaving.
The Blues host the ACT Brumbies in the semi-finals on Friday night.
"It means a lot, obviously I'm a born and bred Auckland boy and I never really thought about going anywhere else. This is home, it will always be home," Ioane said in the video.
He has not revealed which Japan club he is going to.
"But, at the end of the day I've had to make a hard decision and I've decided to leave the Blues at the end of this year."
Ioane was born in Japan and under rugby's international rules could be eligible to play for the Brave Blossom at the end of next year. With connections to Samoa, he would be eligible to play for Manu Samoa too.
"A tough decision, wasn't easy. I just thought it was time. I've been here 10 years, since I was a young kid coming out of school. It's something I never truly thought was possible, I'm truly grateful for the opportunity I've had.
"It's going to suck leaving, but on to what I think is bigger and better things for me and where I want to be, when I want to finish rugby.
"It's not just me and my partner I have to worry about, it's about making sure I've got the means to look after my family.
"That was part of the decision to head to Japan and make the most of what I think is the back end of my career."
-RNZ