In Auckland, Eli Katoa underwent emergency surgery to remove fluid from his brain after suffering a seizure on the sideline.
The medical emergency followed a head injury during Tonga's Pacific Championship match against New Zealand last November.
Katoa had been ruled fit to play twice after head knocks, including one during the warm-up.
After a third blow, the Melbourne Storm back-rower failed a head impact assessment and was removed from the field.
The repeated clearances were a failure of international rugby league's duty of care.
"Today is the one-year mark," Katoa said, reflecting on the incident.
He has not played since.