His combination with Kieran Read and captain Richie McCaw had an emphatic influence on the team fortunes and it's hoped he can recapture the sort of form that made him one of the world's best players.
Since Kaino left, the All Blacks have used Adam Thomson, Victor Vito, Liam Messam and Luatua in the No 6 jersey but Thomson has joined the exodus to Japan, Luatua has just started while neither Messam nor Vito have nailed the role.
It's likely he would be used by the Blues at No 8 with Luatua at No 6.
"He's a Blues man and I would love to have him,'' coach Sir John Kirwan said of Kaino in July.
The lure of playing in another World Cup appears to have been strong, especially given the financial incentives to stay in Japan, where he reportedly earned about $1 million a season at Toyota.