Leana de Bruin has continued to defy time after signing to play for the Adelaide Thunderbirds in next year's Australia's national netball league.

The former Silver Fern defender turned 40 on Sunday but couldn't resist a crack at the new competition after being contacted by coach Dan Ryan.

She had been in the process of considering retirement.

"Definitely shocked because here you are, sitting on the cross roads of whether to retire or what road you're going to take, and then an opportunity like this comes up," de Bruin said.

The Australian club had a forgettable first year in the league only managing one win in their 14 matches to finish last, something De Bruin is keen to address.

"I know they're a very proud club and they have won a few championships, so it's a chance for me to help them to be more competitive."

It was tough decision for the captain of the Northern Stars to make after leading the new club through the first year of the New Zealand's revamped domestic competition.

"You do look for challenges and I do miss that international competitive game of playing the Australians, so hopefully I made the right decision," she said.

De Bruin, who has battled an on-going ankle injury all season, believes the competition's structure will also benefit her, with teams only playing one game per week.

She will become the second New Zealander to compete across the Tasman after former Silver Ferns and Magic teammate Laura Langman helped guide Noeline Taurua's Sunshine Coast Lighting to the title this year.

"We know each other well so I had conversations with her after my decision and she's very happy and said I won't regret it."

De Bruin's accomplished international career ended last year having played 138 tests - 104 for New Zealand and 34 for South Africa.

Her son Caleb will travel to Australia with her but De Bruin said it would not be a permanent move across the Tasman, with plans to return to New Zealand after the netball season.