The 32-year-old has played 91 tests for his country and brings a wealth of international experience and a reputation for uncompromising physicality.
He made five appearances for Los Pumas in the Rugby Championship last year.
This season he played for Lyon in France’s Top 14 and has also had stints with Clermont and Leicester Tigers and previously played for the Jaguares in Super Rugby, where he clocked 49 games from 2016 to 2019.
Lavanini is known for his aggressive style and towering presence.
He is an old-school lock — the kind you feel before you see. He is expected to add steel to a Highlanders pack, which remains youthful in terms of test experience.
Coach Jamie Joseph hailed the signing.
“Tomas’ arrival brings much-needed depth to our locking stocks, especially in an area where Fabian [Holland] and Mitch [Dunshea] have carried a heavy load over recent seasons," Joseph said.
"His experience and physical presence will not only support the group but also help drive the kind of competitive environment that raises performance across the whole squad.
“As a seasoned campaigner, Tomas is built for the intensity of Super Rugby. His reputation for physicality speaks volumes and I am sure he will embrace the challenge of the competition."
Lavanini follows in the footsteps of fellow Pumas player Pablo Matera, who won a title with the Crusaders in 2022.
The Highlanders have also welcomed Argentinian players into their ranks before in the form of prop Mathias Diaz in 2014 and outside back Martin Bogado in 2023–24.
Lavanini is looking forward to the opportunity to play for a New Zealand team.
"I’m incredibly honoured to be joining the Highlanders, a club with such a rich history and affinity to Argentinian players," Lavanini said.
"New Zealand rugby has always stood out for its intensity and pride and the Highlanders play with heart — something I respect deeply. I’m here to bring experience and a hunger to compete.
"I’m excited to work with Jamie, meet my new team-mates and help the club achieve success."
Lavanini is expected to arrive in Dunedin early in the new year. — Allied Media
