Retallick came off in the second half of New Zealand's 16-16 draw against South Africa in the Rugby Championship.
It sparked fears Retallick could miss the Rugby World Cup, which begins in Japan in September, but Hansen was more optimistic on Sunday.
"He's only dislocated it, which means that there's a good possibility he could make the World Cup," a relieved Hansen said.
"No timeline yet to when he's going to return to play, but hopefully he'll be available to go to the [Rugby] World Cup."
The All Blacks are in Pool B for the Rugby World Cup, alongside the Springboks, Italy, Namibia and Canada.