Retallick to miss Boks test
Retallick to miss Boks testSHARE
Retallick was rested for the All Blacks' 36-10 win over Argentina in the Rugby Championship on Saturday and was scheduled to join the team during the week.
"Brodie and his wife Niki have lost their baby boy prematurely, which is incredibly sad news," Hansen said in a statement.
"We're feeling for them at this sad time and our thoughts are with them and their families,"
Retallick's wife, Niki, had been pregnant with their second child, after the pair had a daughter last year.
Sam Cane, Ryan Crotty, Lima Sopoaga, Liam Squire and Sam Whitelock, who were also held back from the Argentina Test, have already arrived in South Africa.
The All Blacks go to South Africa having already wrapped up the championship after the Springboks drew 27-27 with Australia on Saturday.