"I can't believe that you're gone little brother," he wrote. "It hurts so much. You've been called by God to be with him. Although it's tough and we are struggling to understand why you had to go so young but I know you're in a better place. I miss you so much man."
The grieving All Black, who played against the Springboks and the Pumas last month, will likely feature against the Wallabies after Hansen confirmed fellow loose forward Luke Jacobson and first-five Josh Ioane (who was added to the squad for development purposes) were both out with concussion and won't be travelling with the team.
Hansen admitted to some concern over Jacobson's mystery head knock but said no replacement loose forwards will be called in as cover.
"We've got enough players," said Hansen. "That's why we took the big squad. Obviously there are concerns [about Jacobson]. It's like all concussions, you've just got to take your time and when they're ready to play and train you bring them back.
"We're not sure with Lukey. He doesn't recall anything, but he's had a concussion before. It just may be a form that has decided to come back. We'll take our time with him and get him sorted and go from there."
The All Blacks – who have three tests remaining before the World Cup – are hoping the concussed duo will be back available for the second Bledisloe Cup test in Eden Park a week after the Perth clash.
