The Chiefs flanker is one of four uncapped players in the 39-strong group for the first two matches against Argentina and South Africa.
"I didn't really see this coming at all," Jacobson said.
"I thought I'd missed out on the selection because someone told me that you're meant to get a call before.
"I was like 'oh well, sweet as I'm a bit gutted but I'm still young so I've still got plenty of time' sort of thing, so getting named was pretty cool."
