Tua began his career with Northlands in the New Zealand Championship before the Auckland Blues offered him a first taste of top-flight rugby in 2018.
He moved to the Canberra-based Brumbies in 2023 and played 31 games, scoring five tries.
“People will be aware that centre is a position that we’ve had great strength in over a number of years,” director of rugby Rob Baxter told the club website., external
“Through age and players moving on, that’s slowly changed in terms of experience. So it’s an area we’ve been wanting to strengthen.”
Baxter added: “Unfortunately, he’s arrived with a neck issue which he picked up towards the end of last season’s campaign… and it’s likely that he’ll need an operation shortly which will require a period of rehab.”