Ryan, who has been Crusaders forward coach since 2017, was in Fiji when he got what he calls the surprise call from coach Ian Foster.
He was appointed assistant coach at the weekend as the All Blacks reshuffled their coaching roster following the 2-1 loss to Ireland.
Ryan says while he's still getting his head around all the calls, he's loved his brief time with the team.
"There are a lot of moving parts to the All Blacks machine but the boys have been outstanding, he said at Tuesday's training session in Wellington.